greetings porsche fans...new member

[Devo986]

Hello! Bought a 2003 Boxster S last year and love love love it. Had a question for the forum, hoping someone can help:

I'd like to put spacers on to move out the tires and give the car a bit more of a muscular look, esp from the back. I saw some folks used 23mm rear and 15mm front but that seems too big! What's the largest size spacers I can use without any risk of rubbing or bottoming out?

Thanks gang!

Devin