You really can't beat the older Towncars for low budget, high comfort and very reasonable running costs. Just be prepared, as with any higher mileage car, to shell out for repairs as normal wear and tear takes it's toll. Let's face it - 90% of limo companies would not choose the Towncar if it weren't supremely cheap, comfortable and reliable.
I've owned four now, ‘87, ‘88, ‘90 and ‘93. Each offered ample comfort for very little money. I have also owned a lot of other cars - some older, low budget cars, some new, very high dollar vehicles - so I feel my perspective is quite informed and balanced.
My ‘93 now has 123K miles and over the last few months I had to decide whether to spend money replacing those parts that tend to wear out between 100K-120K or to sell the car and move on. Right or wrong I decided to take the plunge and spend the money because contrary to the previous reviewer’s experience, every single item on my car is in fine working order, nothing rusted or troublesome. To be honest, that's the way all of my Towncars have been - the only exception being the analog clocks on the 87 & 88 cars that usually quit around 1 year old.
All four have provided low cost motoring returning 22-27 mpg depending on type of driving. Not bad for such a large car. While not performance cars, these luxury barges are certainly not sloths either.
Repairs I have done in the last 5K miles include replacing the brake pads and discs front and rear, shocks, tie rods (3 of the 4 were still in OK shape, but squeaked a little), tires and replacing the air suspension with coils. The transmission started slipping about 10K miles ago, but a little anti-slip additive has proved a surprisingly effective solution so far, even if that fix is running on borrowed time.
It's worth noting that while fixing / replacing the air suspension can be very pricey, there are coil conversion kits available that are much cheaper and still provide a very good ride. I was lazy and had someone else replace mine and it still cost $200 all-in, compared to almost 10 times that for new air suspension.
As with any other car - if you buy one that has not been maintained you will have problems - but if you buy one that has been looked after and budget for replacing routine wear and tear items, these cars are an absolute steal.