I have had several slow leaks on the tires on my tubeless garden tractor, snow blower and also my stroller. Not sure if it was rim leaks or dry rot but there is a lot of tread left and I hate changing small tires because they are so painful. Slime is worth saving my time and nerves and all these tires are ready to go and no more slow leaks. Yes, cards are great. When it comes to your car, if you can't fix a tire problem, then get new tires.