Extended warranty on a 2013 F10 M5 v/s ??

[f10k]

Hello folks,
Looking to get a used F10 M5 (2013 or 2014) with M/T.
A newbie here, i might be asking dumb questions.. so try to go easy on me (if at all possible ). There seems to be plenty of 2013 M5s available.

What are some good extended warranty options that are out there?

So, if a car is modded suspension/exhaust, would that make that car ineligible for after market warranty?

Never owned a BMW before, coming from Subaru, Honda N/A cars.

TIA.