What you can do, which I have been doing recently and it's working great, is go to a hardware store and buy some interior/exterior multi-purpose 100% Acrylic adhesive caulk to fill in the gaps and imperfections before you move on to the next step as far as sealing the foam (which I already had my pieces coated in plasti dip and it still will work on sealed foam too). It bonds, fills, and seals and it's flexible. It's paintable of course too :thumbsup. You can buy the squeeze tube kind and its cleans up easy with warm water. Just use your fingers to get in the gaps and wipe away the excess with a towel and warm water. I do have one caution, for those who are using plasti dip to seal your foam, use the spray can and not the brush on method on the caulked area (after the spray dries, then use can brush or spray it for more coats) because I noticed that the brush on plasti dip is strong enough to start removing the caulk (maybe it wasn't completely cured but that's what happened in my experience). Hope this helps!
