Just opened my set that I got when BBTS had the (brief) pre-order. Had to look at the video reviews to figure out why I couldn't get the trailer to attach in truck mode. Turns out I'm not stupid, mine was missing the cross bar that also serves to clip the BFG Luckily that really doesn't affect robot armor mode. Amazing upgrade. I had kept a UM/Skywarp 2-pack sealed all this time and finally broke it open since I didn't like that UM looked no different than OP without the kit. So glad I was finally able to get it without the eBay markups.