I had some question about getting an audio upgrade in my 1992 xj6 sovereign/xj40. I was at Bestbuy earlier and one of the geek squad guys said I would need to look online for a dash kit to get a new deck in. Im not an audiophile or anything I just want my car to sound nice. After getting the deck in i'd like to replace the 4 door speaker and the 2 rear deck speakers along with switching out the stock amp and replacing it with a new one and putting a sub in the trunk. My main question is how can I take out my existing head unit and replace with a newer one and what parts do I need such as trimming and dash kits and stuff. Where is the stock amp located and whats the most cost effective way of replacing the amp and putting a 10" or 12" sub in the back. I think the 6 speakers are pretty straight forward they're all 4" im not gonna try and squeeze 5.25 subs into the rear deck. Any help would be appreciated, thank in advance.