My independent Volvo mechanic recommended we get this fixed on our 2007 XC90 3.2. I declined for now. Reading this thread, I'm wondering why he quoted us $450? Maybe a whole new vacuum pump? I think I'd rather DIY it with this rebuild kit.

I just did this on the very opaque headlights on my '07 Xc90. Came out pretty good, considering I wasn't being anal about it. Go to your local auto parts store and get the Mothers Headlight Restore kit. I think it was around $22 bucks. It is basically some polish and a small foam powerball you stick...

Just did the Seafoam TB treatment yesterday (about 1/3 can). After the requisite smoke show (the car smokes for about 5 minutes while the crap that has built up is burned away) the 240 had a pronounced bit of kick. Rest of the can to go in the crankcase prior to the next oil change.