Before I purchased my Boxster...I was at the local dealer asking about the pits of owning a pre-owned model. I spoke with the mechanics in the shot and basically they said the same thing. Get PPI first from a dealer, and if it checks and you buy it, drive it like the wind. That is what it was built for. No regrets here either. Now, the suspension knock is either the rear shock or the bushing in the control arm or the police chap you ran over. Being a Scott, I will have a keg with you.
