I bought one once and it went into the round file, just chalked it up as a loss. Then a couple of months later, it was like I was haunted by a nightmare, another one showed up in the mail and I didn't order it. This one's up in the attic somewhere.
There was also a resin conversion set for Revell's 94-96 Impala SS to a Caprice cop car. I doubt if that place is still in business though. It came with a trunk lid, grill, hood ornament, and hub caps.
I don't transport any of mine in cases, but for the ones not in cases, I use an appropriate size box and put a couple of layers of cotton t-shirts on the bottom and around the sides. It supports the model without breaking the wheels off, they won't move or tip over in a panick stop, and the shirts won't scratch the paint. I don't let the shirts touch fragile parts like mirrors or mud flaps on big rigs.