Car just painted, Now having an engine issue

[Tweetdriver63]

I'm sure it's just Murphy's Law kicking in (Pay money to have something cosmetic done, and immediately start having a technical problem), but maybe not.

I just got the Boxster back from getting some new clothes (I post pics tomorrow). I'm all dressed in matte black with red trim now. Thing is, since I got the car back, I've started having an idle issue when I first start her up. She's running very rough, with idle RPM dropping pretty low and then coming back up, then after a few seconds (usually) the RPM bumps up to about 1200 or so and smooths out a bit. Today, after we were in a restaurant for about an hour, when I started it up it was particularly rough, and I even got a backfire when I gave her some gas trying to smooth it out! Once I'm moving, she runs fine.

Is it possible that they didn't cover up the air intake on the driver's side when they were spraying, and paint got into it? Would that cause this behavior?