PPI recommended/needed when vehicle has warranty?

[jiggz]

Hi everyone - 1st post here on xbimmers. I've owned a few different 3 series over the past 11 years but currently looking for an X5.

I'm looking at a 2011 w/ 30K miles so it's still under BMW's factory warranty, but I feel like a PPI would still be a good idea. Would this be a waste of $? If I purchased it, what restrictions are there for bringing it in under warranty? Do I need to report something wrong with it to make an appt.?

Any input would be appreciated.

-Jeff