It seems like the AIW employee who went to the bank with JW would know what car he was in, but it wasn't mentioned. It seems that is the likely car that he drove to drop off the money in. If it were the Porsche, that brings up a lot of questions. If it's his own car, that bodes better for him to be separated from that car during those couple days. Would be great to know.
If it was the Porsche, it brings up the big question of when did he obtain it. I doubt SS allowed him to take the car home overnight. So we don't know how SS arrived home that night and we don't know what car JW was driving the next morning when he picked up the package at the bank but police know.
JMO