I did a cut and fold on my rear quarters. I'm about to order some seam sealer and was wondering what everybody uses. The kind that comes on a tube, a brush on can? Any brands better than others?

Urethane would be my guess. http://www.ebay.com/itm/111457697357?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT

On the inside: 3M Flexiclear, bought at any parts store. Drys nice, and flexible/paintable

On the outside: bedliner of choice, even a spray on one from a parts store would work good.

3m in a tube has done me good over the years.

All the 3m products made for that are good.

They are all pretty similar to be honest. I used ACDelco when I did my floors.