^^^He's right, be careful out there. This is a business like everything else.
Number One Sound can make any custom audio work to suit your ear buds. I've seen plenty of custom work on many cars including for Alpine.
All I can do is recommend them as I've experienced half my life with them and I trust them with car audio advice and installs.
I'm also very picky and love quality sound. I used to have an MKII Jetta Diesel that rocked (with only one sub!). I had guys think I had 12's (yes plural), but that body style was also great for bass too. When sitting in the front, it sounded like you were in a concert. Sweet highs and precise beats...I really miss that sometimes. My music is now hearing the mechanicals and exhaust note from the E12..
Won't hurt to give them a call and maybe go by and he'll show you the type of custom work they've done in the past and continue to do.
Good luck wherever you end up going.