I have been doing car stereos for 30+ years . I enjoy doing loud , clear systems - but my passion is the bump of the “sub” , lol . Doing a sub in a vert offers a unique challenge - first you have a tiny trunk to work with. Second , when the tops down the sounds dissipates .... so , to overcome this I used 2 ported wedge truck boxes behind the front seats with some 8s in them . You are limited to average depth speakers though ( but these type tend to need smaller amps ( this less power drawl from the stock alternator ) I also put a single 8” dvc sub in a small sealed box in the passenger foot area under the heater box . And to add some boom - a ported 8” box in trunk ( where the 3 amps are ) all my subs and amps are 90s equipment and dirt cheap used ( quality was awesome for A/B amps back then ) the head unit I went new ( to get Bluetooth and avoid CDs ) pioneer headunits have great power and the ability of built in low pass / high pass crossovers let’s me send only mid frequencies and highs to doors and back speakers ( so I did not need an external amp for them (they sound surprising great for being powered by only by head unit .) all and all I spent less than $250 for total system , and it sound great ! Let me know if you need any advice , I really enjoy talking shop , lol .