Bought new in 06. Now has 143k miles on it. Over last 2 years, lots of little repairs that have over time added up. Last 6 months major problems. Already completely replaced brakes ($800), changed sensors and valves ($500). Alternator has been making loud noises for a bit. Automatic passenger door doesn't work. Now my mechanic says I need a new radiator and I have an oil leak that may be serious (gasket?), and my transmission is starting to fail. I was really hoping to get another 50k or 100k miles out of it since it is paid for, but I really don't want to keep putting money into it if the vehicle is going to keep having major problems. My concern is that it has now crossed that "point of no return" line and is beyond reasonable repair. Should I fix it or just take the repair money and put it down on a more reliable used car??