It is good if the sedan has a latch on the backseat that opens to the trunk like an accord...or in your case...grand prix which I would classify under muscle really not sedan. but my car is way smaller than that. and just changed to a hatchback 6 months ago.
as for pin being cold on winter...i can see that but i'm dead set on giving this warm fishing gloves that the wife gave me to try.
get the gloves for typing on touchscreens, their nice and thin but warm ive used them for casters, my pin a couple times and my spinning setup it works for all