Extended Warranty

Anxiously awaiting arrival of my '12 528i (black sapphire metallic). I didn't extend the warranty on my '06 525xi - not thinking I would keep the car beyond the warranty period. As a result, I paid dearly - $3,000 transfer case, etc. replacement a year ago. Definitely learned by my mistake. Are there any restrictions, cost or coverage penalties in waiting to extend? Just curious, as I'm pretty sure I'll extend the warranty at the time I pick up the vehicle.

I am getting ready to extend the warranty of my 535i since my wife loves it. I was told no restrictions or penalty. I'm coming up on 45K