Is it possible to maintain/repair a 987 Boxster for $100/month?

[Perfectlap]

Well if you plan to keep the car until the 90K mile mark you have to remember there is maintenance and then there is major maintenance.
Oil changes, air filters, tires are not bad for this car given the rewards.
When it comes time to change shocks, clutch/flywheel, IMS, service axle boots, rotors, 02 sensors, parts that fail prematurely (starter, alternator), etc. that can add up to a figure north of $6K. If you aren't setting a little aside for major maintenance in addition to annual maintenance then you're going to have to break open a few piggy banks. It's best to tackle one big item each each year in addition to the regular maintenace...spread the hurt.
I spent about $6K on major maintenance recently and it was well worth it because this is car to keep for the long haul. The engine still sings, the paint still shines and I still get at least one compliment per drive on a car whose design is 17 years old.