I bought a black-on-black 1998 Mark VIII LSC two years ago (2007). The previous owner had purchased it new (fortunately for me), and also took good care of it (also fortunately for me).
He installed an after-market perfectly balanced aluminum drive shaft (which I was going to do, but saved me the cost) ; had replaced the entire rear neon light unit (unnecessary, but nice -- now I have a spare, since I fixed the first 'broken' one). Otherwise, he only changed the oil regularly and changed the Transmission Fluid once.
The car has been EXCELLENT, an absolute dream to drive since I bought it! The factory brakes finally gave out about 4 months after I bought it, and I replaced them with black-painted (keeps the rust out and from dripping on the wheels) drilled and slotted rotors and ceramic pads. They look great, don't drip rust, and stop the heavyweight very well (although in retrospect, I should have upgraded them to larger rotors... but that can be done later) However, I STILL like better performance from it, and have a difficult time finding the right parts for it (even though the engine is the "same" as a late-1990's Mustang Cobra).
I put on some nice, black, 18-inch wheels with low-profile tires, which helped increase gas mileage and maneuverability, installed a huge free-flowing permanent (oiled) air filter, high-performance Bosch platinum +4 plugs, and plan on more upgrades eventually. With the traction control, what is sometimes mistaken for an "old-man's car" can wipe any competition within miles! Also, knowing that its top speed is now over 220mph helps, too, LOL! (Check the 'Utah Flats' speed test the engineers did on a stock Mark VIII LSC -- over 200mph -- something Mercedes and BMW couldn't even come CLOSE to!).
PEOPLE, FELLOW MARK-VIII ENTHUSIASTS, PLEASE: IF there is something 'not quite right' about your Mark VIII, then there is something WRONG! Even if it's that you wish it handled potholes more like a luxury car than a sports car -- it SHOULD! Mine does! The airbag suspension changes automatically with speed and driving style/conditions. A pothole down a sideroad (or on the expressway) should be felt as a slight nudge, NOT an annoying or painful bump.
Also, be prepared to do a LOT of research to let mechanics know what is BEST for YOUR car -- NOT the other way around! A high-revving idle? Check the thermostat first (if it's broke, the engine won't ever think it's warmed up -- and revs won't drop as they should)... and work your way up from the simplest to most complex (a computer or computer module problem).
Want to replace spark plugs? OK -- BUT BEWARE! If you remove the COP (coil-on-plug) ignition, it MAY NOT go back on with a good connection! The springs on those are VERY weak -- and often rusty and almost worthless after removal. YES, I had the problem -- I eventually got a good connection, BUT - my next upgrade is a set of Granatelli Power Sport (highest voltage short of racing set -- and they don't cause warranty problems) COP ignition coils, with the SOLID, stainless-steel stem connector. MUCH better! Should also add another 30hp to the engine.
After all this, the car IS, after all, over 10 years old, and needs ALL its rubber bushings, mounts, etc replaced -- preferably with polyurethane, or better; poly-graphite. My problem is finding ones that match.
Also on the list is front and rear shock-tower braces, and (IMPORTANT) a frame-firewall connecting brace, which should alleviate any possible cracks in the firewall steel due to power turns and high acceleration. I love being able to take 90-degree turns at 30mph without feeling the car lean, "cruising" at 90mph with the engine still just under 2000rpm; jumping from 15 to 70 in about 3 seconds on the on-ramp; all in the relative SILENCE of this masterwork of automotive engineering!
The 10-disc CD changer (STILL not worth trying to find something better...yet) and JBL sound covers any other possible noise.
OH, alright -- there are two things I don't like about the car.
1: The funny little fuses they use -- very difficult to tell when they're burned out. (NOTE: Check these for non-heating seats; suspension control, and other inoperative items.)
2. Lincoln STOPPED MAKING THIS CAR!! Yes, this is a BIG problem -- the lagging sales COULD have been made up by marketing the car as more of a 'racer' (one team DID build a Mark-VIII NASCAR, but Lincoln REFUSED to sponsor it!)... on the grounds that they "didn't want a 'racing' reputation." The engineers LOVED the idea -- and would have made an amazing car AWESOME in a few short years -- but of course, the 'execs' said "NO", and over 30 years of a GREAT line of cars goes down the drain! SAD. (To put it mildly).
ANY of the MARK-series cars are STILL eye-catching and great to drive... In my retirement, I plan on assembling a collection of these classics, to restore, sell, save, and remind people what a great company Lincoln used to be. Who knows? Maybe a miracle will happen and the powers-that-be will re-introduce the MARK series (the REAL ones, not some off-the-wall oddity that has the same name). But I'm not holding my breath!