MB Vinyl

I just had my seats recovered in vinyl. They look better than the leather I had , feel softer but one small problem. The vinyl is a little baggy running up the sides. When I pointed this out to the shop where it was done he told me the vinyl will shrink over time.
Is this a lot of cr...? Or is this true. He told me to speed up the process ,when the car has been in the sun a long time and the seats are hot spray cold water on them.
Anyone had a similar experience?
Larry
'86 560Sl

[G-Benz]

Not on my MBs, but I have installed vinyl seat fabric on my Bug at least two times in its life.

The shrinkage issue is bull! You can get small wrinkles out immediately after installation with (careful) application of a heat gun, or exposure to the sun (and the water spray trick).

The location of the anomaly will not get the desired shrinkage unless you remove the seat and orient the affected area directly towards the sun. Again, this only works for "small" wrinkles.

Otherwise, the install needs to be corrected.