I have a 2008 328i. No one inspected my car when I purchased the extended warranty. They just read your key to get the info they need.
Yes, you should buy from a dealer that will negotiate the price with you. I was able to get $800 off of the retail price. I also did not pay tax.
You should check out Cobb Tuning for your tune if you something that is easily removable. They sell an Access Port to load tune, change maps, monitor/log your car, and clears error codes.
http://accessecu.com/cobbtuningweb/p.../features.html