I have owned my 71 Challenger since 79 and my 70 GTX since 81. I bought these cars because they were affordable and powerful. I kept them because they were affordable and powerful. And a blast to drive everyday. I would always get the MPG question and when you don't make a car payment, you have money for gas. They were easy to work on and you could beat on them and they would hold together. I drove them the way they were built to be treated. But they had the oil changed every 3000 miles with good old 20w-50 and a nice tune up every 25000 miles or when a plug fouled Now that I have kept them, I get the reply... man you were smart to hang on to those gas hogs, they are worth a mint. But they were practical for what I needed and I had fun every time I went out in them. They don't hit the streets every day now, but when the weather is nice and I feel the need to exceed, I hit that distictive Chrysler starter whine and its on Keep it on the road, thats what I say... have fun in them and let someone else figure out what its worth when I lick all the red off the candy. I think you can't put a price tag on the enjoyment you will get when you drive them.