Boxster S - Rear Strut Failure?

[linderpat]

Also, you were pretty brave (or foolish) to continue driving it home after seeing that (unless you were a couple of blocks away and on a slow road). I would have immediately put the spare on.
As to your shop questions, I always use indy shops with good Porsche reputation. dealers are never a good deal if you are out of warranty. Likewise for parts - buy from the known vendors. Dealer mark ups tend to be very high.