Wanted to update this thread with a link to this one:http://forum.arduino.cc/index.php?topic=196047
Not TX#/RX# related - but does show an interesting relay/mosfet (at least, I suspect this) based "hybrid" h-bridge setup for the drive motor.
Also, I recently purchased a couple of toy RC cars, that were made closer to a hobby RC car than other. 4wd, full independent suspension - but likely "bang-bang" steering, though there does seem to be some kind of feedback (probably limit switches - I haven't delved in deep enough).
Anyhow - the cars are called "Extreme Machines Thunder XX" by Xin Yu Arts Toys Co., Ltd. - there is a 49 MHz and 27 MHz (standard toy RC pair) versions; they look to be 1/10 scale. They use a TX2/RX2 pair - and the h-bridge for the drive motor is a pair of SPST relays (while the steering is done via a discrete transistor or mosfet h-bridge). 9.6 volt NiMH battery, Tamiya connector. Not sure on motor size, but brushed (not brushless).
Cheap, but seemingly effective. All plastic construction, except for drive shafts and such; it must have some good torque, though, because the drive shafts on one of the vehicles I have are twisted slightly. Fairly easy to take apart, re-lube, repair, etc - but as with anything plastic, things tend to easily break or strip out (JB Weld to the rescue!).
Just another vehicle to keep in mind!