[Frodo]

Do a search...there's TONS of info on both at this site.

Basically, they're two different issues. RMS is, relatively speaking, more of a 'nuisance' issue, though obviously it's a good idea to get it fixed at some point.

IMS failure is typically in the 'catastrophic failure' category, but one never knows when or if it's gonna happen to you. There's little to no warning. Opinions vary as to the percentage of these engines that suffer from these failures, and Porsche ain't talking. In your search, you'll learn that there are now well-engineered retrofit IMSs available, and a lot of people have opted to go for them. I probably will as well, as I am getting to the point where I need to get a new clutch and the dis-assembly is the same for both. There is also now available an 'IMS Guardian', a warning device that tells you when IMS death is imminent.

Read up on Jake Raby's posts about both. Reading ALL the stuff available on IMS/RMS could take you most of the day, but it's good stuff to know.

As long as you monitor your oil level, your car is certainly driveable at this point.