All Boxster's are prone to RMS and IMS failures, but they tend to be more common in earlier years. Also know that once you get past 35-40K miles your chance of having one of these problems decreases but that is not to say it can't happen.
If your seeing oil leakage, a tell tale sign of an RMS problem, I would not try to postpone fixing it. Your risking a pricey engine replacement vs. a $600 US seal replacement.
Also, IMS has nothing to do with a seal. The only warning for this, is if you hear a faint sound that sounds like a coin bouncing around in the engine compartment. If your really concerned with IMS, there was a company a while back in the UK that was selling modified intermediate shafts, that they claimed were failure proof. I can't recall the website, but someone posted it a few months ago. I'll look for it.
