Questions about Rear Main Seal

[bigwatts]

Greetings All,

First time post here. I joined the forum a little while back and have spent many hours finding out information I never knew about my boxster.

My question is as follows:

There seems to be a lot of issues with rear main seals. I recently purchased a 97 one-owner boxster from an individual. It has 78K on the clock. I had a pre purchase inspection done and my mechanic did not notice any oil leaks. What causes the Rear Main Seal to go out?? Is it something I need to concern myself with?? The original owner said it was never replaced to his knowledge and I can't find anything about it in the service records I have. When shopping for my boxster I found some similiar vintage cars that had the RMS replaced at 60'ish K. From reading this forum I also notice that the clutch should be replaced when the RMS is done. How muct time can you expect to get out of a cluth on these cars. I have owned many older german cars including porsches. My 968 had 155K with the orginal cluth...and it had no problems at all. BMW's with even higher miles. Just thought I would ask. The clutch seems very strong and the tranny shifts like butter.

Thanks in advance for your help.