Questions from a new boy - suspension noises

[sam1977]

Hi - I am now 3 days into Boxster ownership: I bought a 2001 3.2S 81,000 miles, last serviced at 75,000 miles. Very good condition. Bought in the UK and I am now about half way back to home with it (south of Spain) - I have a couple of issues:

Rear drivers side (right side looking at rear of car) has now developed quite a pronounced squeak. When I open the boot and push it up and down it sounds like an old mattress! Possibility covered in road crap from two days of 500 miles a day driving? Or more common problem?

Also over rough surfaces, only at slow speed, there is a non-metallic knocking sound which sounds like its coming from the rear suspension as well.

Actually I my 996 Turbo has pretty much exactly the same knocking from the rear suspensions which is something I expect to be picked up in the service for that car next month.

Any ideas? Also how often do these cars need to be serviced?

Car is fantastic by the way - I absolutely love it - so balanced to drive. I love my 911 but this is just as good (just not quite as fast basically).