There's the fundamental problem, right there. I don't think I'm alone when I say that I don't want to race YOUR old car, I want build and race MY car.

I think you might get more traction trying to start a Novice Buggy Only class. Speaking for myself, that's something I very much enjoy (when it happens.)

I like the idea of $350 sell out price but I think it does not have to be RTR and you can set price for each of the significant components so you don't have to part with the whole car if someone claims it. Like say you can claim the motor for $50, the chassis for 200, the esc for $65, servo for $65, so on and so fourth. Also make certain part of the car not claimable like the body etc. Store also need a ready package that retails for cheaper than the price you set so anyone can jump in and be competitive. I would suggest cheap spec motor and fixed gearing ratio. I would also set a max number of time you can claim someone else's car or parts per season so no one is abusing it. Also I think you should not be able to buy other's car or parts unless you already have a setup to race with.

I think this have been done in Finland for weekend real car racing series and works quite well.

If something is done it should be there and now. I could see something like this in a large race but not weekly club racing. Unless everyone runs the same chassis, body swap would be a pain. What incentive does a person have for winning?

I'm not convinced a price cap is going to level the playing field if people can run what they want. If companies really do start building cars tailored for this kind of class, then people are going to feel the need to replace their ride with the next best thing rather frequently. $350 per ride won't help much if you go through several of them per season.

Also, I saw no mention of motor restrictions. What's stopping a good driver from getting a really cheap car and sticking in a cheap modified motor and blowing through the field? The newbie who sees this car would buy it out, and be unable to drive it and end up breaking it at the next race. That newbie won't be coming back again.

I would not be thinking of manufacturers getting involved yet. Gotta prove that anything like this idea could work at a single track first. Let alone thinking on grand scale. The 2 tracks in my area don't even seem to acknowledge the other exsists.

We've been running a for fun only 1/18 for 3 years. Started with Associated mini Apex, then the Dromida trucks took over. Last summer was good, 10-20 people every other Sunday. From 5-70+ in age. Had high hopes that this summer would be better. Turnout had been down this year, but still fun. While we run as road course, jumps could be added easy for buggy or trucks. Simple 5 lap sprints. Crash your out.

https://youtu.be/nIihNc4TPz4

$50 motor
$175 chassis
$50 servo
$50 battery
$50 ESC

No reciever, no body.

I think you would get people spending those prices or less to compete and leaving the high dollar new/older chassis for other classes.

Also, if someone running a lower dollar chassis gets claimed they would be ahead in $$$ but possibly without a car to race until they replaced or claimed another person's.

How about using the Traxxas 4 tec 2.0 as a spec class for onroad sedan? $300 on amain (coupons would make it cheaper).

Tamiya Euro truck doing real well here. No Mods. except ball bearings, all kit parts must be used.

There are couple places that were trying to get this going. But haven't read of any actually running.

Traxxas doesn't allow the use of the discount coupons.

It's tough to say if it could really work. We run mine on our course layout. Works. Thing is it's quicker then what are the already established entry touring car classes. A year ago I wouldn't have though this. But after getting in to TC racing this year. I get it.

Then the hard part is actually getting people to show up.

Our track owner did an invitation only race earlier this year. He provided the RTR cars, batteries, and spare parts. We painted the bodies, charged the batteries and drove the cars. The cars were collected after each race and passed out at random for the next race. There were really no tuning options except shock position but some of the racers did add weights to make the cars heavier. Once it was discovered it was called out as illegal. The racing was fun, but it really didn't do anything to "level the playing field". At the end of the series the results were typical, the people who were on the podium in other classes took the top spots while those who didn't took the lower spots.

I'm not sure how many would actually run the class if they had to buy equipment and then be told that they couldn't modify anything and someone else could claim the car after they put it on the podium though.

The purpose would be to have an affordable, easy class to enter into racing. Ideally no one would ever sell their car as it should not be more desirable than a brand new one. My local track is inside of a Pole Position raceway (fast indoor electric carts). It gets a great deal of people with no previous exposure to rc racing stopping by to take a look. They are clearly interested in what we are doing but are not willing to drop a $1000 on it. It would be nice if there was truly a class that a complete newbie could buy an inexpensive RTR and be able get racing immediately. A gateway vehicle and class. I realize this would not be for every veteran racer with multiple $1000+ cars. I however just might buy one for the fun of it.
I truly fear for the future of rc racing. When I was a kid I raced (all goldpan rc10s) in an under 16 class. We had a full driverstand every race day. Today we have one, sometimes two, under age racers and they are usually thrown into the novice class with adults. An inexpensive RTR class just might bring more kids and new adults to rc racing.

This is sort of like the Tamiya Euro Truck class and the Tamiya Spec novice class. The cars are cheap and easy to get started with.
These are great classes but I think some improvements will make the concept even better. First is to have a spec tires that is cheap, will make the car handle predictably and long lasting. I think the ride radial tire fits the need well. Second it needs body choices that will make the class attractive. Maybe a scale looking GT class will do the trick. The Euro Truck and Spec novice class falls short on some of these items but are still popular which shows the viability of low cost spec classes.
I hope something similar in off road can be established. Maybe a traxxas based class?

Might work. Though you might have to restrict the veterans from racing in the class. If you don't, they too might start racing it for the fun of it and the true novices will not get the same racing experience as they will be constantly trying to stay out of the way of the faster racers. If you're only trying to address the affordability though it might work. One of our local racers is trying to put together a class around a TC4 chassis with spec motor, esc, servo, body, & a few tire choices. His goal is a sub $300 car sans radio and transponder. I think we forget how much all the accessories cost though, even if you can get the cost of the car down you're still going to need batteries, transmitter, transponder (most of the time), and tools. All of which add up quickly. Rather than a spec class I was throwing around the idea of a buyer's guide that new people could reference to see the real costs involved. Haven't managed to complete it yet though.

I love to try this. About closest I've ever heard of would be a Slash rental class. It's a catch-22 thing. For a track owner to be willing to try, there needs to be new people actually at the track. And that's the hard part. How to get new people to just come out to the track. Honestly, if the group I'm racing with now had not decided to race at local store. I would not be racing.
As much as I'd like to have tried even just running practice laps. Not all tracks are welcoming to new race driver. I've got one with that reputation in my area. A new place did open in last year. Just not easy to make trip. Toll roads and high entry fees would more then double for me.