[Perfectlap]

I did the RMS Cayenne upgrade but it wasn't leaking before then.

If the RMS is leaking on that 2.5 there's a possiblity that the new seal with leak as well.

I'm not sure I would consider a 2.5 even it weren't leaking. For a little bit more money you can get into the next engine regime (2.7) which addressed a lot 2.5 engine issues and added new upgrades. Either way budget $2K on swapping out the RMS and clutch. There's no such thing as a buying into Porsche on the cheap.
You'll just end up regretting not having gotten something better from the start.