Please Help: High-End car audio

I am very happy with my Sony ES head unit/CD changer and a 50 watt x 6 channel Precision Power Amp (PPI) combo in my BMW 535i. It is dead quiet, even when turned all the way up (with no signal of course), which is very important to me. I hate hiss. I used Wireworld Orbit cabling throughout the car, which I purchased in bulk from Wireworld for $4 per foot. I believe this cabling is a big part of the excellent sound I am achieving. I am using Infinity Beta series drivers all around - 1 1/4" silk dome tweets in the door pillar (stock location), 8" mid-bass in the kick panel, 5 1/4" midrange drivers in the rear deck, and a 12" Beta sub in a sealed enclosure firing into the car through a ski bag hole behind the rear seat center armrest. The Beta series is now discontinued, but was their top of the line driver series (above Kappa), and only available from Infinity's "best" dealers (read: highest volume). Associated equipment includes Infinity's passive "competition crossovers" for the front stage speakers, (the 5 1/4" mids are run full range with their natural rolloff), a 1 farad stiffening cap for the amp, and Tiff fuse/power hardware. My suggestion to you is to explore new head units (Sony ES and Macintosh sounds like a good idea too) and upgrade your amp to a nice PPI or Extant unit. I'd stick with the Focals for now, and I'd also try some high quality cable like the Wireworld Orbit or your favorite brand shielded interconnect. Incidently, I am 30 years old, like accurate, deep & tight bass (not BOOMY), and my car system has won awards at sound quality competitions. I do NOT compete in the SPL contests - I am only interested in sound quality, not quantity! Good Luck on building your dream system!!

Ezmeralda11- I can think of several factors that might affect the sound:
1. Some head units provide a lower than typical preamp voltage that would definately affect the ability of the amp to provide great sound.
2. the $70 price for installation is a steal. We're talking 3 pieces of electronics, x-overs, and multi component speakers. I paid about $250 for install on my eclipse system which did not have a separate changer. Many shops would charge $70 just to install an amp.
3. The long IC and wire runs from dash to trunk and back would accentuate any problems there. I hope you bought and received (see #2) good quality here.
4. The amp is, IMO, another likely source of the problem.

Cars are exceeding difficult to get right, everything is even more application specific and there is little if any opportunity for a meaningful audition. However, I would see if you can get the dealer to swap out the amp, and double check on cabling. I would recommend ADS amps, but they will cost at least double what you paid.
3. The amp could have a significant impact on sound.

From Poster to Swampwalker: The amp and speakers I installed myself, the $70 was for both indash units (the changer and the cd receiver). The eclispse claims a 5V preout on my unit which should be sufficient (the one above it had an 8V preout). I've noticed most others start at about 1.8 or 2v and top of at around 4.5v. Now I don't judge the units solely on that number, but I should have enought output (not to mention the amp does have gain to accomadate weaker signals). The interconnects are 16ft runs of Lightning Audio Strike series. The interconnect and speaker cable are down the passenger side and the power and remote lead are down the driver side. At this point I still don't know what to do. To me the sound is "stuck in the drivers" if you know what I mean. It doesn't have that ethereal quality where a sound sounds like its coming from behind the tweeter or something, there's not much air or ambience.

From poster: If its of any consequence the amp is mounted on 3/4" particle board which is then mounted to the metal floor, so its not touching any metal (it even has the rubber sleeves for the screws). All connections are simple crimp on spades. Mids are running full range and tweets have there lows filtered via a 12db high-pass crossover (which I had to build, single coil and cap, I did all the soldering). Speaker cables is 16gauge radio shack. I figured if nothing else, since it wasn't the best amp in the world, give it a little help by lowering the overall resistance giving it slightly better midbass control for a couple of bucks. I don't know if the Nakamichi is the ticket.

Ez- You're right, the 5v output should be sufficient. Sorry, I can't say much about sound being "stuck in the drivers". My Eclipse set up (w/eclipse speakers) is in my Jeep Cherokee with a rack and box on top. At 70 mph, sometimes its hard not to drive the 50 wpc ADS to clipping. But when I'm stationary, it sounds pretty good, tonally. But I'm not looking for imaging. One issue might be where the drivers are mounted. I have the mid/woof in the standard front door cut out and the tweets on an angled surface mount provided with the eclipse, on the kick panels facing up toward the driver. Anyways, I would try swapping out the amp first to see if it helps. Should be easier than re-doing the head unit.