First BMW. . . . EVER

[SquattingDog]

Greetings guys and gals, I have been reading this forum for the past couple of months, and what an incredible wealth of information.

As a former GM engineer, I have owned nothing but GM products for the past 25 years. Well, I did buy a 2010 MDX that I still have and do like a lot. I purchased my first BMW EVER 2 months ago, a 2011 X5d with 13k miles on it. MSRP of $75,200 and I paid $53,500 (from a Ford dealership that bought it at auction!). I think I got a good deal. I must say I am a convert - I didn't know what I was missing all these years.

Anyway, I have a couple questions if anyone would care to answer -

1. Last week, I wanted to see what would happen if I left the rear hatch open while backing out of the garage. The result - the rear glass shattered. My insurance company tried to get me to use Safelite, but then offered to pay $850 minus a $250 deductible if I went OEM. My local dealership repaired it for $1200, and I need to bill Nationwide. Anybody have any luck getting Nationwide to cover the entire cost?

2. The front tires - 20" Dunlop Sport Maxx RFT's - will need replacing soon. I am happy with the ride (Sport Package with Adaptive Drive), but my tire choices are sooooo limited. Is there really a big difference going from RFT to non-RFT's in the ride quality?

3. Anybody have any experience with Hendrick Auto's AutoGuard extended warranty? It's backed by a subsidiary of Hendrick Automotive Group (which my BMW dealership belongs to), which I think might hold a little more weight than an independent third party extended warranty. Cost is a bit less than BMW's extended warranty but I am wary of any non-manufacturer warranty.

Thanks in advance for any input!