bass tubes are ok... but if you want subs... that dont sound like crap... you can have them actually mounted to the rear panel where your factory speakers were... a good audio shop can build a custom enclosure for them as well... a local audio shop quoted me $300 for 10 inch subs and the inclosure all mounted to the rear panel... the only draw-back is that you lose your stock 6inch speakers that were mounted there... but as long as you amp the front speakers it will sound koo... ill look for a picture of a setup like this to show you...