I bought my 2003 S-Type R with already upgraded audio. Head unit (teouchscreen + nav) is not changed, but there ar following mods:

- Alpine MRP-F300 4ch amp
- Alpine MRP-M500 digital mono sub amp
- custom subwoofer in the trunk
- all speakers changed wiht hi quality 2-way components

I ordered ACM from USA, cause I left all cd-s behind and listen only digital files.
Hope to post some pic's soon

Jaak

 

Alpine 4-channel and bass amp in the trunk:



Bass level control place is chosen smart:



Woofers are in factory places, no interiour changes:



Tweeters are separately at near-ideal places:

 

jaakennuste:
What does your sub look like? Pic please...