A few months ago I bought a new car. This morning I woke up to find a flat tire and this is the first car I've owned with no spare. I couldn't pump any air into it so didn't attempt to use the pressurized foamy gunk that comes instead of a spare. I called the dealer who advised not to waste my time with the gunk if it wasn't a simple puncture that I could see. I called the AA ( = US AAA) who arrived in 10 minutes, jacked up the car and confirmed that an inner side wall had split then put on a temporary spare that they carry around and then followed me to the dealer.