None of the MPs are dead-on likenesses with their G1 cartoon counterparts. Reasons fort his include:

* Reality. Cartoon models cheat reality all the time, which toy designers/engineers simply cannot do IRL. Bumblebee has an additional challenge of having a robot mode based on the Penny Racer proportioned Beetle, but the MP is attempting to achieve a more realistically proportioned Beetle.
* Vehicle accuracy vs show likeness. e.g. MP20 Wheeljack looks more toy-accurate in vehicle mode with all the Alitalia colours, decos etc. The cartoon model lacked any of this and has far simpler colours. So the toy is caught between trying to achieve vehicle accuracy in car mode and show-likeness in robot mode.

* The G1 cartoon was far from being consistent! Shades and shapes varied wildly between different animators. It looks pretty darn close to me.