This isn’t about work on a Studebaker, but the problems can be common. I installed carpets in the ’54 some years ago and they worked out really well. No real wrinkles and just a little less than perfect fit in the rear footwells which has improved over time and use. I believe I bought them from Rene Harger. He is still in operation and advertises in Turning Wheels.
Problem I’m into right now is removal of big wrinkles in the truck carpet I’m trying to install. The carpet was formed well enough over the trans hump and in the front floor areas, but to each side of the seat there are large wrinkles from the carpet trying to lay over curves going in different directions. Above is the left and right sides. One as bad as the other.
After doing some reading online I found that steaming the carpet does work sometimes. So I borrowed the wife’s clothing steamer to give it a try.
I gave them three or four good steamings and then put weight over them each time and let the carpet cool. The weights are bags of sandblasting media. Forms well over the hump.
Success was so-so at best. Still have wrinkles, but not so big. This will have to do and hopefully the seat overhang will hide the worst of it. There is also a chance that summer heat from driving will help it all to fit better.
I think the steam idea is good, but for wrinkles in flat areas or maybe in an effort to stretch the carpet to fit into the floor contours.