So I've managed to nab MP 17-20 and am now looking at picking up Sideswipe and Red Alert however I have no idea how to identify the authentics from the knockoffs that are all over the web for these figures.

Whilst most of the listings specify KO's, can you guys give me some tips on picking fake ones from legit? E.g. are the boxes identical? the cars out of the box when pictured identical etc.