I've heard some good things about the lineup that kenwood has this year. Based on Sound quality is this the best brand to go with? Good model retails for $179 with 50w x 4 max. and 3- 4 volt pre out.

 

I am assuming you are talking about a HU? Max power doesnt mean squat. Look up the WRMS power rating. Probably between 18-22. Depending on the MY of your S, the stock radio is between 7 and 14ish WRMS.

I have never heard an Excelon HU personally, but have heard good things, especially about the 25th anniversary model. The pre-amp outs are typical...nothing too special. Most HU's have a minimum of 3 pre-outs with 4V ratings. This is only used when using an external amp. If you are going to be running an external amp, no need on spending mad $ on a top-of-the-line HU, as you will be bypassing the internal amp and will be using the amp x-over controls for the filter.

Out of the box, I like Alpine and Pioneer the best. Pioneer I think has a 12bit digital converter, which is quite nice sounding. Look into the Premier models of Pioneer. Also check out the Alpine 9851 and the 9855. These are the upper end, and go between $200 - 300 on ebay.

John