Body putty for seams

On my duster I used a couple different types from my local body shop. It's right around $8 a tube ( looks like a tube of caulk but is actual seam sealer). I used a tan color sealer ( autobody master brand) and also used a black sealer ( transtar brand) both worked great. And bot give you more aesthetically pleasing seams as they not only seal seams but level them.

I etch primed and 2k primed the car and then used the seam sealer and then primer sealered the car to lock it all in. And then base cleared the car. It all came out great.

If you look in my build thread ( link in signature below). I'm sure you will see a lot of pictures of the sealer.

Good luck!