I have an area under the tailgate of my Jeepster that is hard to access, but may collect water and cause rust. Does anyone know if a sealer of some sort can be sprayed (shutz gun maybe?) through a 2′ or 3′ piece of flexible tubing? I have also thought of filling the void with spray foam (messy) or seam sealer (hard to verify coverage).Any other Ideas would be appreciated. Thanks.