So, at what point do you cut your losses and buy a new(er) car?

Here is the situation: I have a 1985 244 turbo intercooler. Blue on black leather. M46 4spd+OD transmission and 241,000 miles on the clock. Bought it in 1989 with 42,000 miles.

Recently blew the headgasket and decided to "overhaul" the bottom end as well. This included a new oil pump, rings, and rod bearings in addition to the work that I had done up top (new guides and seals).

This engine actually ran very well for its age and mileage. Before the gasket blew compression was 150-155 psi on all four cylinders, and it burned barely 1/2 quart of oil between changes, but I decided to rebuild the motor anyway under the pretense of keeping this car "forever."

Within the last 8 years, I have also replaced the clutch (original at 168K!), OD solenoid, center carrier bearing, rack and pinion, engine wire harness, turbo cartridge, blower motor, catalytic convertor, down pipe, radiator and rear suspension bushings. Cosmetically, I had a local upholestry shop rebuild the driver's seat. I have averaged approximately one "major" repair per year during this period of time.

So, where am at I now? I have an engine that runs like new, a drivetrain that is probably average (tranny makes a little noise in 3rd gear but still shifts well), and a body that is above average to excellent. The car has been garaged and washed regularly all its life. It is a N. California car with no visible rust - anywhere.

I think that I have also contended with most of the common mechanical faults, or wear and tear issues, that these cars have as they age. Would I be insane to expect another 100,000 miles of service from this car? Or will I end up replacing parts that I didn't even know existed.