I have been having a play with an E4 RS, it has some great ideas, but also some teething issues.
Quite a few of the teerthing issues are being solved, and many of them have been rectified in the 2009 model.

A big point to note, is that some wheels will hit the front arms under steering lock, all you need to do is add 1.5mm of spacers at the hex, and 90% of wheels should clear, it will look on the bench that they dont hit, but when running it hits, and will cause the car to hop in the corners. Its not a biggy considering out of the box the car is so narrow, i think mine was in the very low 180's

Check the outdrives rotate in the axle cups smoothly, for some reason one of mine was binding the suspension, i swapped them left to right and all was ok.

Check that the shocks do not bind, mine the pistons were a little tight in the shock bodies, i just put the shaft in a dremel and polished them down a little on some very fine wet and dry.