[thstone]

I'd like to inquire about your current suspension set up and why the need for racing slicks, but I'll just answer the question;

The typical camber plate will provide ~1 deg over stock (so you might get right around -1.9 to -2.1 deg total camber). Very few (if any) camber plates offer enough adjustability to get to -2.5 deg of camber.

Alternatively, some people modify the upper strut mount area (drill out a wider section in the sheetmetal) to get more adjustment. Personally, I do not like this method (IMHO its a bit of a hack) but some have done it successfully.

Otherwise, to get -2.5 deg or more of negative camber, you will likely have to use adjustable lower control arms.