Mine is standard boxster (non S, manual) and I just went through the painful preventative repairs, car runs fine but I had RMS leak. So far, I have RMS replacement, IMS retrofit with LN engineering bearing, clutch work (got lucky that I don't have to replace the flywheel, 1mm away before the clutch rivets touch and ruin the flywheel at 47K miles), all 6 spark plug tubes + plugs replaced, brake fluid/clutch hydraulic flush, transmission fluid change and AOS change for $3K (parts, labor and tax).
Next phase would be engine mount (has small crack on the rubber, not that bad), water pump and new top, that might cost me close to $2K.
If you need tires, that would be $700 more...
I guess I'm half way there
with all the repairs.....
Just get prepared for total $5-6K repairs and then you can enjoy your car without any worry....