primer for plastic?

I've been to all the auto parts stores in my area, and I haven't found a primer that is specifically for plastic. All the guys working the counters have told me that the spray-can primers they sell won't stick to plastic. One guy told me to buy some Krylon Fusion and use that as a primer.
Anyone point me in the right direction? I'm going to have my bike professionally repainted, but I'm trying to do as much prep work myself as possible to save money.
I did find some plastic primer at ACE Hardware. It's made by Dupli-Color, but it's clear. How the hell am I supposed to know if the surface is even if I use a clear primer? Someone please just list a brand name or post a link to some plastic primer!

http://www.rustoleum.com/product.asp?frm_product_id=357&SBL=1

Thanks!! Wonder where I can buy some... maybe Home Depot or Lowe's?
 
Hey, D2D, can you make a graphics kit that looks like tribal flames from the tribal 600rr's?