Painting the PowerBook

I have got a hold of a PowerBook Pismo 400Mhz. I bought it iff a company a while back and have loved it and don't want to get rid of it. However I come to the conclusion that I am going to kep it, but I want to spray it. This is all wel and good and is a great thing, but I went to the local model shop, asked the attendant what I should use and he was stumped. I then asked the company that I bought it off and they said that the think it's made of ABS plastic or something polystyrene based. As A result I wouldn't want to buy the wrong paint and don't know what do use. Can Anybody help me? What is the plastic that PowerBooks are made of? What sort of paint should I use?

I would be grateful if any of you would be able to help me in this.