I spent from 1983 thru 1998 in Performance Test Engineering at DPG, driving each and every prototype and new model during that time. I’ve owned a few Mustangs from the 1979 to 1990 years, and loved them all. I now own a 1983 GLX convertible (you blew it there, the GLX was produced for just 3 years, '82-'84) with a 5.0L and 4 speed trans (actually a 3 speed with OD), leather interior, crank windows, AC, PS/PB, factory stereo w/o Premium Sound, glass window with defroster, the TRS wheels (which I sold immediately, because the tires are so outrageously expensive). In 1990, Ford went to a roller cam motor for the 5.0L, made a HUGE difference in torque, let alone engine longevity and reliability (esp. if you drove it hard). My car came from southern Indiana, and is 100% RUST-FREE, and was not undercoated. It’s got 37,000 original miles on it, the original top…but I de-polluted the engine, adding an Edelbrock Performer manifold, a Holley 4 bbl carb (getting rid of the stock Holley, it never was a good carb), MSD ignition, shorty headers and Flowmasters. Outstanding cruiser, sounds great, and I love driving it. (I own another Fox, an '86 Thunderbird Elan, with a 5.0L and AOD, it came from Virginia, has 67,000 miles and is also 100% rust-free. I put duals & glasspacks on it; I like it, the wife hates it, LOL. I drive both regularly, and they’re my “babies”. Since I was so deeply involved in Fox development, I have a real soft spot in my heart for these cars.) I would like to point out your claim on rarity of these 7-Up Mustangs; with 4700+ produced, they’re not really “rare”, there’s no premium on them, they’re not collector cars, and offer no advantage over other Mustangs due to performance upgrades or anything, with the exception of the manual transmission versions. They’re green, with white interiors, white tops, turbine wheels and dual exhausts. And that’s about it. 7Up decided that promotion just wasn’t worth going further with, and Ford was the one who decided to go ahead and promote these cars as something other than a regular Mustang convertible GT.