Many New Cars Have No Spare Tires

My 2016 Mustang GT with the performance package doesn't have a spare option. Fords Mustang spare is an 18" rim and it won't clear the 15" rotors and 6 piston Brembos. I pickup a nail on the inside sidewall on the freeway and tried using the mobility kit. After about 10 minutes of trying to inflate it, I had 19lbs of air. Jumped in and got me off the freeway. By then, it was back down to 3lbs. Aired up again and drove about 2 miles, and aired up again. Got to Les Schwab and was informed that I had a puncture on the sidewall and that they couldn't let me leave for liability reasons, and refused to give my car back. They would sale me a new tire though, for almost $400 After threatening to call the police for theft, they let me have my keys. Aired to 50lbs and made it to work. I used my own truck and trailer to get me home. Ordered new tires from Tirerack.com. And the tires that I got the flat with? Only 2 months old, but Big O has no road hazard warranty on tires that are not THEIR brand.