I did a fiberglass enclosure in the spare tire well and theres almost no clearance between the bottom of the sub and the bottom of the enclosure. theres a very loud vibration of two things knockin eachother. im not sure if its the bottom of the fiberglass flexing or the fiberglass hitting the sub. i think that im gonna pull the subs and reinforce the bottom. should i take out more glass from under the sub?