Hey guys I'm planning to add a new sub using the wiring from the rear 7" subs (non-Bose system) on my '96 A8Q ive read through some of the older posts of people who intalled custom subs and i have a few questions. What do you guys suggest Option 1 BTX 250 (2 10" subs, amp and crossover with controls) package tube sub Option 2 CS-1200T tube Sub Soundstream 2ch. Amp custom wiring crossover (Required?) Options 3 Your suggestions? Questions 1) Audi Radio code - is the radio code a 4 digit number? Nothing metioned on the radio card but a CD changer authorization number and another 4 digit number mentioned on the service booklet 2 How do i get all the bass to the sub instead of it beign reproduced along the other speakers? 3) Does the existing(non Bose) system have a built-in crossover ? if so where would it be located? 4) Jacobs has a product that can be connected ot the exisitng wiring to add an RCA Audio in to the system. i need this for the new Capruter ive built. Although im a little worried about the port of the VAG controller. Will there any problems if i splice the wires? I believe there connected in some way.