I apply all of my over-laminates with the Big S.
I have used Lamex UV and Avery clear lams (glossy & satin).
If you call your near-by sign supply warehouse people,
they will often send you a few yards of sample films to test.
Try them out, make some decals and put them on your car or
a piece of coroplast and stick it outside in the sun & weather....
see for yourself how long the various colors and materials hold up.
Lighter weight (2 mil or less) over-lams are harder to deal
with and can wrinkle easily when applied by hand.
I was told to try and use an over-lam that is made
by the same manufacturer as the vinyl you are covering.
Material compatibility/shrinkage may be the issue here.
BUT, even the wholesale brokers like Stouse and Discount
Labels will only guarantee their bumper stickers/decals for
12-18 months.
Hope this helps some.
Sue2