What do y'all think about this idea? My friend did this as shown in the pictures and I'm thinking about doing it also. You would have to remove the top part of the seat belt so they would be lap belts now. Pretty cool idea!

 

If I were you I would buy a headliner that has 4 speakers built into them or I would get some speakers to put behind the seat (if your gas tank isn't right there). My personal opinion I don't really like where your buddy put the speakers but that's just me. The reason being is he over the shoulder seat belt is safer than just a lap belt.