Radi-Can, Race-Tin, Tin-Racer...
  At the beginning there was nothing...or almost nothing...Then Taiyo (time to learn Japanese!) came with its Radi-Can. This new concept of radio-controlled toy was about 1:32 scaled cars (12 to 14cm long) sold in cans with the remote used as the cap of those cans (yes you can take it out ;)). Of course, we are in the toy dimension since car's conception is simplified to the max: a 5 functions chipset to deal with the controls (Forward, Backward, Left, RIght and Turbo), a smart steering system based on magnets, a motor for the propulsion, and non proportional controls.
Return of the clones
 This extreme simplification is far away from a weaknes and on the contrary brings a lot of advatages. First of all, it gives the opportunity to build low cost clones (around 10¤ in Asia retailers), sometimes really well made, all "Made in China". These clones are often called Race-Tin and are generally of good quality. Brands like Auldey, Dark-Horse, Tyco and other less known are the most common. Another advantage that this technical simplicity brings, is the opportunity to customize those cars mechanically and electronically. It's usual to find moded cars that run 10 times faster than the original speed (60+ km/h).
All is well!
 Simple, solid, low cost, available in many frequencies (allowing multiplayers races), all those qualities are the true reason why those small cars became so famous in Asia, USA and now Europe since some models are now imported (how lucky for us :) Hours of fun and amusement guaranteed.
Compare with numbers...
 All right, so, everywhere you read how fast those cars can go. Still, you can't believe how some relays, a slightly different motor and a specific gearbox can transform such a toy in an amazing rocket. The following pictures come from a discussion group dedicated to Race-Tin's version build by Tyco RC, the Canned Heat. Speed measurement are done with Tamiya's Speed Checker: real speed would be a litlle bit lower. Anyway, this benchmark shows how every hint and modification explained on this site help improving the perfomance of the cars. These tests are realized with Auldey cars.
Original speed of Race-Tin is around 5-6 km/h. We can verify this with the Speed Checker (that shows how acurate the Speed Checker is). The Skyline used here is an unmodified model.
Same test with an Audi TT this time, using a wheel kit, and a NEC relay mod. The speed is more than 2 times the original!
This time with a Turbo kit installed, without pressing the turbo button. Checked speed is 24 km/h!
When we press the turbo button, one more battery fuels the engine and we reach 32 km/h.
Still with our turbo kit (and turbo button ON) but with a better gear reduction factor. We finaly reach 60 km/h!