I have a pair of brand new (NOS?) 2-way Phoenix Gold Octane R R57.0c speakers I bought for my LeBaron still in the box that I've been meaning to sell. They've never been out of the box, and have been sitting on a shelf in my spare bedroom for a few years (always stored inside the house). I've always preferred 2-way speakers in the back since they're mostly for bass & fill, or at least they should be--you don't have your living room speakers behind you, do you? :icon_biggrin: You really want your soundstage up front, so spend the big money in the front on high-quality separates if you can work them into your dash/kick panels, or top-shelf 2-way/3-way if not. I think you're pretty-well stuck with 2-way 3-1/2" up front, but several manufacturers make high-end units that will fit. Being that the M-bodies don't readily lend themselves to a lot of interior cone area, a trunk-mounted sub is something I would consider mandatory. Unless you're looking to annoy the neighbors, a single 8" or 10" in a correctly-designed enclosure (not some universal off-the-shelf box) would do the job quite nicely.
Phoenix Gold Octane R R57.0c: 60W RMS/ 120W peak, 90dB sensitivity, aluminum-plated polypropylene cones w/butyl rubber surrounds, ferrofluid-cooled mylar/neodymium tweeters, frequency response 65-20,000Hz. I would still gladly use these if I had a car into which they'd fit, but both of my cars use 6x9s. $40 shipped to continental US if you or anyone else is interested.