Using that as a search term was difficult so figured I'd just ask. Essentially why can it be done for quadcopters and I can't seem to find anything on car transmitters. Would be nice to be able to bind my flysky noble with any reciever. If anything I would think it would be easier to do surface multiprotocol. I'm sure someone here knows why

Just speculation, but I'm gonna say because the quad folks tend to be more into tinkering (as evident by the mainstream use of open source technology, like BLheli ESC software, Naz32 boards and Cleanflight/Betaflight control software and the use of serial receivers). RC car folks seem to be more interested in completely OTS systems and spend more time on mechanical setup and whatnot. Also why FrSky doesn't have a surface radio, otherwise, I would be using them instead of Futaba (nothing against Futaba, I'm just a control freak with RC, no pun intended).

I mean, look at it this way... how many car receivers have you seen where the end user is expected to solder on ALL of the pins? All of my Naz32 revisions came as a pre-populated PCB in a static-free bag with all pins, cables, etc... in a separate bag. Some assembly required? Yeh... "some" is an understatement, lol. Most of these do not utilize a case, either. I feel that if a brand tried to do this in the car world, lots of folks would look at it negatively.

I would prefer to run a serial RX if I could.... one that didn't require a bunch of additional hardware that negated the whole appeal of a serial RX in a model such as a 1:10 car.

For manufacturers it is clearly better for them if their customers are buying their receivers. The companies putting out the multi-protocol systems are new manufacturers without an incentive to keep customers locked in to using legacy products.

Manufacturers are also always pushing for the lowest possible latency, and introducing new proprietary protocols for surface systems. These new protocols usually aren't backwards compatible even within the same brand's range, again to encourage the purchase of the latest and greatest transmitter.

As someone relatively new to air radios, it seems that the protocols stay popular for longer and that there isn't this same continuous push for ultra-low latency, except perhaps with some of the new TBS crossfire gear.

Even an air radio with a multi-protocol setup like the TX16S or J12 doesn't work with every receiver, but certainly a wide selection.

It is also possible to use the TX16s with two modules at once, and has the ability to act as a receiver and transmitter at the same time. For air use this could be used to make a wireless trainer/student setup. I'm interested in trying whether I can bind a surface transmitter to the TX16S in RX mode, then use a second module to transmit to the vehicle. This would allow for some of the more advanced modes and mixing from the air radio to be triggered and used from the surface radio.

Airplanes/Drones/Helicopters are usually always connected to a computer or something so it is easier to manupulate settings and configurations. Not to Mention most that use crs dont even get into higher end radios. its 90% RTR crap now. also once one make the jump to a high end radio you usually just stick with that. a friend of mine actually ask me this question yesterday. and that the only reasoning I can come up with. I just dont thing there is much market/Need for it.

Where as my Air stuff I have Blade/Spektrum, FrSky, Futaba, Hubsan, Crossfire, etc. Just got the Radio Master TX16S so I can incorporate all into one. just have to actually do it..

As a manufacturer, would you alow the use of cheap other brand receivers?

Not to mention warranty claims......