What brand of kids e-vehicles is the most hackable/modable?

[swade]

I'm thinking of those little electric jeeps and cars that 3-8 year olds drive around my block. My wife is pretty keen on one of those for a Christmas present for our little ones. I'm game as long as I can *upgrade* it.

I'm looking for a brand or model with a bit of a community of people who have modified them. Does anyone have any links for where to start?

 

[mettleramiel]

Those powerwheels cars are really esy to upgrade because there are no controllers involved, just on/off switches between the motor and battery. All you need to do is add higher voltage. I've turned a 6volt version up to 12 so far and a 12 up to 24. Not sure how much more the motors could handle as I ran out of batteries, but you essentially double your speed right there.