NO, it's not just for packed trucks, i see this blur on wheels for standalone trucks also, just wanted to confirm
BUT, yes you are right it's most obvious on packed trucks on trailers....
I noticed it to in the live build the other day. The whole vehicle blurs a bit like its a ghost image of the cab about 3 times over in motion from 1st person... The tires are most noticable with a mudflap arm going up the tire 2 or 3 times too. Thought it was the new nvida driver i got the other day.