This is a great system http://www.wheelspinmodels.co.uk/item/CM20...nce-5400__2366/ they do other KV ratings aswell they do a 4200 and a 6800 but if you are just driving up and down a car park i would stick with the 5400 it's not to fast and not to slow, but i have heard storys that micro rs4's are uncontrolable with bl set ups so it's really up to you