Yeah, Sonic's site kinda sucks in that regard....
Buying used is not a bad way to go because you will have to paint it regardless. As long as it has not been hit, you're good to go, but Im not sure how much cheaper you will get it compared to Sonic's price and most people selling are trying to get some of their investment back. Pros and cons.
I paid $200 to have mine painted by Ashburn Collision and most shops in the area should be in that range. I don't know who Sonic uses for paint work, if at all, so you will need to check with them on that.
I'll try to steer Porsche Pat over here to answer your questions and maybe you can get him to update their website as well.
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2011 Mineral White M3 ZCP - Opticoat, Ventureshield, some CF, B&B exhaust, AFE Intake Vorsteiner VFF 101s Ohlins
2014 Mineral White 328d Xdrive Wagon - Opticoat, Ventureshield, B8s, H&R, Apex SM-10s Hawk Pads
2021 718 Cayman GT4 - Fire extinguiser