My son(7 years) usses anything, as long as it's not to aggrassive and sticks on the road. Right now he is using the Audi R8 FSI 5.2 (he does 'cape ring-backwards' in less than 3 minutes).
Well.. tell him to pay good attention in school then, because for most people 129,000 Euros (163,500 US$), which is what the car costs over here, is quite a lot of money to pay for a Japanese car.
Is that what they cost in the Netherlands ? you can easily get an R35 GT-R for £40,000 here in the uk.
But on track with the thread my 6 yr old loves driving the kart, other than that most kids will go for Lamborghini's,Ferrari,Zonda,concept cars because of how they look, best way is to just turn everything up esp skid recover, abs, tcs. turn on driving line & explain what to with it and let him choose his own car.
Start off with a simple track High speed ring is best due to it being wide,simple and not too many gravel traps (1) (he will have much more fun this way ) set him off and after 10 min tuition leave him to it you will be surprised how quick they start doing clean-ish laps then over time start removing the driving aids.