[Jeff Chambers]

Going the Xcal2 route, the car is flashed through the OBDII port. So as long as you can lock the flash device away from Junior's reach, he can't undo your changes.

With the 4-bank chip, a switch and cable can be attached. Use one of the four program slots for a speed-limited tune then take the switch/cable and lock it up away from Junior's reach. Junior can always go in and pull the chip though so this isn't kid-proof.

In either case, the person creating your custom tunes can set speed limiters and rev-limiters wherever you want them.

The other day I was playing with my 01GT looking for some fuel economy. I set the rev limiter at 2500 to try and train myself not to go WOT on every shift. I'm about half-way through the tank of gas so I'll have to let you know if it worked for mileage's sake but it is keeping me from shifting hard or going much over 65mph with those 4.10's in fifth gear.