Thanks for your responses. Does that mean the Tamiya spray cans acrylic lacquer will adhere to the plastic better due to the lacquer thinner?
Probably, though it could craze some plastics. I've had no problem spraying directly on styrene, but "your mileage may vary". Its best to dust on the first 1 or 2 coats anyway, so that may be the saving grace.
I tend to use primer on all my models. The Tamiya lacquer spray primer on any material and under any paint. I've also used Velejo primer on styrene and under several different aqueous acrylic paints (including Tamiya) with no problems. I would not use the Velejo primer under lacquer of any kind.