I have a 2007 “justacooper” with the HiFi system. I have been considering three possible basic configurations to upgrade the audio:

System 1: Focal Polyglass 165 V2S (2 way), Alpine PDX 4.150 amp, JL Audio W1 10” sub. The sub and electronics would be mounted in the “false floor” type enclosure in the trunk. The rear 6x9’s would be abandoned in place.

System 2: Focal Polyglass 165 V3E (3 way), Alpine PDX 4.100, Focal Access 6x9 coaxial in the back, no sub.

System 3: Same as system 2 with Focal 165 KPS (2 way) in place of the 165 V3Es.

I can't decide if the subwoofer option would be worth the cost. Also, I don't know how much of a line output converter I "need" and how much Dynamat to use. Line output converter options include the Audio Control LC6i, Rockford Fosgate 3Sixty.1, or 3Sixty.2. Dynamat options run the gamut from (1) just behind the door speakers to (2) the whole car.

Prices for System 1 with a 3Sixty.2 and one Dynamat bulk pack installed is about $3000 and require two days to install. Which option would you choose and what would you do to reduce cost to about $2400? Installing it myself is not an option. Regards

 

I would use the stock amp, add a sub, and Dynamat the whole car. The OBC has to see the HIFI amp whenever it gets a software upgrade. So, if you replace the amp, you have to be able to put the OEM amp back for any work done on the electronics in the car.

If you make your installer aware of that issue, perhaps he can figure out a way to deal with it.

 

According to my dealer, they can do a complete software update without the amp present.

 

If you don't mind me asking, which dealer is that? Because that would really simplify things for my upgrade if they're right.

 

I would keep the stock amp and the stock 6x9's. Get the 3 way focals and a 4 way amp that can sufficiently power them. Get the signal for them from the front channel with an inexpensive LOC (no more than $30). Fade the head unit most of the way to the fronts.
Run around with this for a while, see if it acceptable to you. if not, get the hidden sub and power it from the bridged rear channel of the amp. If you decide not to use a sub then you will only have wasted the extra money for 4 channels instead of 2.
I wouldnt bother with the rears.....

 

mini of south atlanta.