My grandmother use to use them to cross over to Reno back when she owned the car. I still have then althought they will not fit my new wheel/tire combo. Wish I would not have forgotten them when TurboBenz and I took his SD over the summit on I-70 and down into the packed snow of Denver earlier this month.
They are for emergency use only... but its better to have them and not need them then not have them when you need them.