Any advice on car audio?

Don't waste too much money on a car system.
You can go all out like Mr. Campbell advises, but it costs time and money. How much time do you really spend in the car? Since these car audio companies change their lines every two weeks ;-) it's easy to find something decent on sale too.
I'd rather spend around $500.00 for a good head unit (CD receiver with removeable face and 4 x 100 watts - Ha ha), upgrade the speakers if necessary, and be happy.
You'll never get the car to sound like your home system. Save your money and spend it on music and upgrading the home system.

sorry to stray from the topic but:

is there a single driver speaker made for cars?

I like the idea of no crossover and would rather sacrifice the high end in favor of better mids. I hope to hear a good single driver speaker for the home someday as well.

Phil

I second Golden_ears on most points.My introduction to music
reproduction began in car audio.Started in '78 and retired few years ago.Done a few great set-ups.The better sounding rigs really are ground up projects,choosing a good vehicle
picking out equipment,improving electrical system from stock
and interiors as well.In the end you have issues to which only more "stuff" in the signal path helps.The good news is
the entry level gear is a bargain now(If you don't get bitten by mobile theater bugs)I alway advise start simple.
Remember thieves abound and loud rigs advertise best.

Start with your front stage.Pick out a head unit with good ergonomics(remember you may not be only driver on the road with electronic distractions)I dig units w/steering wheel remotes,several brands have that option or hanheld ones for
relatively cheap.Mosfet amplified head units are now very common and start at under 2 bills includes digital domain parametric equalization.Go for efficient speakers
well placed 2way seperates in lower kick panel pods seem to work best.Upgrade paths can be more power.Tweeters can be added up higher in dash and powered by headunit.Infinity makes nice very flexible efficient powered sub.Thing about
autosound you should keep in mind is that cars are noisy enviroment(70+db background noise,best demo is sitting in a parking lot or the stores display)They have complex electrical systems and many digital sytems now,and boundary effects,oh my.
So start small clean efficient.Place your speakers well.

Philjolet, the only single driver units I am aware of have those paper whizzer cones in them. Typically they are on the low end, price wise and I am sure they aren't intended as anything but a cheap, full range speaker with limited ability. They do make good coaxial speakers but separates are really the only way to go. Getting the tweeter placement higher up in the car and properly positioned is the only way to get anything approaching stereo separation. Anything less is just so much noise coming from your door panels.

I was into car audio for quite some time and built a number of systems (separates & subs) for my cars including a 1984 VW GTI, a 1988 Toyota 4Runner, a 1988 Porsche 911 and a 1994 SeaRay 180BR...yes...a boat...then I got into home audio and never looked back...now I wish I hadn't wasted so many $$$ on car audio that was either stolen or sold with the vehicle...sure it sounds nice, but I find that the less I listen to music in my car now (with the exception of road trips)...the more I appreciate my music when I get home. Just my 2c

Ellery