Insert Backer Rod into Large Gaps

so one little handy tip we got some pretty big gaps here we're trying to fill always have backer rod in your vehicle that way you can get these cracks back them up with backer rod then i'm using tower tech 2 elastomeric sealant to go over that and that way your caulking will be able to span the gap of these huge cracks like five and one wherever it's really big now i won't have to fill this whole gap up full of caulking