I've always hated this figure, in its many molds energon fattimus prime is ugly, but the happy meal toy is the worst by far. I hated the white chest and red arms, it looked like the love child of a female magnus and prime, ugh perish the thought.

Anyways heres what I did, ripped out his energon cube light thingy and filled him with a smooth car body filler, then filled his arms as well.
then straight repaint in true prime colours and details. Tah Dah done, took 1 hour to fill and 30 mins to paint. used plasicoat grey and gold, acrylic red and gloss blue for the hands.

If anybodys noticed I'm working through my junk primes at the mo ..... well thats just prime...... its not going to be forever, I do own a large quantity of other transformers and other action figures, however the flavour of the season is prime. I own more bumble bee and megatron junkers and repair jobs, the rest of my primes are perfect and this may be the last one. sigh of releif? no I enjoyed messin around with details.