This is a very good important question. My 4Runner 96 V6 has 285,000 miles and runs fine after transmission and engine were done. I bought it for 3,000 at 202K miles. I have replaced LOTS of parts on this car to include axle and driveshaft. Brakes, Starter, all belts and hoses.... I bought an ENTIRE new interior seats and all for 300 bucks, the body is in good shape. Everything works GREAT, sunroof, all windows, but...there WILL be more to do. I have never done the rack, other steering components, coil packs, fuel injectors, alternator or O2 sensors. There is no CEL now. Clearly MORE is going to go. The fuel gauge is reading incorrectly when below 1/4 tank. Ok, I DO have somebody that will do the heater core for 200 bucks labor so that's pretty good. Question is when do you stop refurbishing a car? My thought is that if the interior and body are in good shape, you can rehab it forever. But do people DO THIS? SHOULD I DO THIS? WHEN DO YOU CALL IT QUITS? When you need to replace the ENTIRE REAR AXLE MAYBE? WILL THIS COME TO PASS? WHO out there has put huge rehab money into old 4runners? Lots of Comments welcome!