Compare the 2010 versions.

Hey guys I need help!
I've purchased my x6m on 4/23/2010 (total purchase price was 100K). On the day of June 7th 2010, I was driving on 605 freeway at 75mph, suddenly 'low oil light' came on the dashboard. So I got off to the next exit which it was about .75 miles from where warning light has came on. When I got on the exit ramp, car has totally shot down. I was very lucky that car had enough speed to roll to the sidewalk otherwise I would have stuck on the traffic going 70mph. When I pulled over to the side. I notice smell of something burning (not really strong but very noticeable) so I open up the hood and to my surprise there was no oil cap and little bit of smoke was coming out of oil refill hole. After I closed hood, I called my salesperson and explained to him what had happen and he suggested me to call road side assistant, which I did and had towed in to local BMW Dealer (Shelly BMW in Buena Park, CA).
At the Dealership service adviser said that car had only 3qts of oil and that was the cause of engine burn out. Since it's owners neglect, it'll not cover under BMW warranty. I told them the car only has 1500miles, I never opened the hood. Why should should I? There was no warning light and car was running fine 'till it stopped on the freeway. Plus,day before when I did 'system check' everything was O.K..
She said there's nothing she can do because it was the decision from BMW North America.
Oh yah, she mention that since BMW is not at fault, bring the loaner back and tow your car out of the dealer.
Here's letter from BMW North America.

After reviewing this case in person unfortunately BMW will not be able to provide warranty coverage based on following findings:
No oil fill cap. Vehicle driven with substantial lack of engine oil (4 qts) (originally service adviser said 3 qts) without concern for the resulting engine damage.
Please feel free to convey our finding to the customer and if they choose to romove the car from the store I will flag the VIN in DCS. This is a decision based on the overall warranty criteria that there has to be a defect in workmanship or material and neither was found in this case.

After I received this letter, I've contacted dealership I bought the vehicle from (Savage BMW in Ontario, Ca). They said they will have to follow the decision and there's nothing they can do.

This is more upsetting because salesperson told me to baby it for first 1500 miles. it burned out at 1517 miles.

Hey guys, I need your opinion:
Should I have checked oil cap, before drove off the dealership?
Should I have checked oil level, daily even there's no waning light?

Any body know a good lawyer?