Please help
Go with a "Real" RC if you can, I've had alot of experiance with radio shack and I'm so happy I got in to the "real" RC cars instead. What might help beside the getting some sort of a better ESC you could try (If your handy with a Soldring Iron) to resolder the critical areas of the CP chip with a good quality Silver Solder.....RS usually uses lead based high resistance solder that has alot of resistance. Just think, if you get some sort of real RC you could also mess with gears, get lots and lots of motors, a much longer running range, and it will last longer (Debatable to users). One more thing is you might want to get some 12 or 14 Gauge wire, btw don't screw with the servo wires, it will totaly mess your car up if you get the right one. hope this helps
Gecko