I did have an issue with the only Speedster I brought in from the U.S. It was titled as a VW, but was clearly not a VW. The young female customs officer objected to the car (she saw it outside on the truck, through the office windows), but I persisted. I claimed I had all paper work correct, and had followed all procedures, with copies of bill of sale, title, proof of purchase price, and all import forms filled out correctly, etc.
An older male officer heard us and came over, and told her he would handle things.
He basically knew what I was doing, and asked to look at the paper work, and said, OK. As long as the paper work is correct, that is what gets filed away.
So, it may depend on which agent you get to deal with. Remember to have all paper work delivered to the U.S. customs at point of exit three days ahead of time.
Do not tell anyone you are exporting/importing a Speedster - you are importing a 71 VW.