Your car analogy is a good one...with one minor problem....
The scale that we're talking about is vastly different. The cars aren't the only thing smaller with RC, the market is smaller, the profits per unit are much smaller...but the overhead is still pretty significant.
Also consider that the 'car' portion of an RC car is actually a pretty small component in the RC purchase. So it would be like purchasing a fleet of 4 vehicles, and having a problem with one of them. The dealer will work with you on getting the problem vehicle fixed or replaced....not all 4.
I agree..they should back the customer on the car...as far as the electronics and whatnot...there's no problem with them....if they are still unused..then depending on how the request was made, the shop might take them back..blustering and making threats or demands will likely result in 'final sale'
If the electronics had been installed or the batteries assembled then I can't see the shop taking them back even if they do accept a return on the car.....
A shop will be much more willing to work with you if you interact with them in a respectful and business-like manner. The shop didn't generate your problem and they stand as much to lose from the ordeal as you do (you're our some time and money, they're potentially out the proceeds of your future business) They WANT to have you as a satisfied customer. If you start yellign and screamign at them for somethign that wasn't their fault...then they won't go to bat for you since they may likely prefer NOT having to deal with a crappy attitude on an on-going basis....
just my $.02