Well, you made a good buy and as long as you take care of it, which is what you seem to be doing so far with making sure you run 93 and using fully synthetic oil. I would get on those plugs next and if you're ok with changing them every 15K to 20K miles, I would use Autolite Copper 764's gapped at .054 but if it will be daily driven, go with the platinum plugs and you'll be good to double that. Might even get better gas mileage with platinum's. I have always ran the 764's as have many on here but I think my next plug swap will be over to the platinum because I'm not out here trying to race everyone. I just want to drive it normal and last me as long as possible.
Mark VIII's on here have been known to still be rolling up to 400K miles and still running fine. A lot of them on here are well into the 200K range and still running fine. I feel like mine is just now getting broke in. There are a lot of people out there that have no idea what a Mark III is. I myself have always wanted one since 1993 when they were $40,000 but I couldn't afford a car like that back then. I always said that I would have one someday and this one is my 3rd. My dad totaled one (93) and I literally blew up the 94 which I finally bought in 2005
If you ever get the chance to test drive one with air ride, give it a shot and see what you think. You'll feel the difference. Some on here have converted but they put good money into their conversions to get the ride they get. Then there are some of us that will never let the air go.