1999 Subaru Legacy Outback Wagon Limited review from North America

At around 130,000 my Outback started giving off this funny smell and running hot sporadically. I took it to our mechanic, and get a phone call saying that the heads are warped, they have to go to the machine shop to be re-surfaced, there is exhaust in my cooling system and and the entire cooling system had to be re-done. Along with the entire cooling system, I opted to go ahead and have all the belts changed, have a tune up and over all re-work my car so I can drive the wheels off. $2500 later. Fast forward 4 months, my car starts running hot sporadically again, I take it back to the same mechanic 5-6 times, as they were trying to duplicate the overheating. They replace the radiator cap, thermostat and finally the car is back right now having the whole cooling system redone again (exhaust fumes in the cooling system - seems like I have heard that before), fortunately for me at no charge because I have a great mechanic who stands by his work even though it might not be his fault...

I must also add that my mechanic now has two other Subaru's in his shop right now, having the same problems...

I am unsure if when I get this car back, if I should keep it and hold my breath for this problem to happen again, or can I go with my original plan to spend a small amount of money (as compared to the purchase of a new car) so I can drive the wheels off???