For a lack of better term, its like a factory caulk that dried rock hard. I want to get under it to hit some rust and paint, is there any material out there that replicates this? Its around the car in various places where seams would be, etc.
it's seam sealer...... yes you can buy it...I use a urethane based seam sealer. stays more like hard rubber rather then getting rock hard
(http://i233.photobucket.com/albums/ee79/daminc/Doors/IMG_3965-1.jpg)
can you paint over it or are you stuck with white seams?
It's made to be painted over
Of course you can... I used about 12 tubes of it on my car before it got painted