This idea came from others here in the forum...so thank you to the many that have done this. Where the bottom door doesn't quite seal to the trailer side, these will fill the gap. No sewing needed: just tie a knot!
I did a similar version of this. First I purchased towels to match my interior decor. Then I sewed them into rolls"snakes". Next I filled them with beans. These made an excellent weather draft stopper. The internet gave many types of fill that can be used. Just measure the area that needs to be beefed up.