So a massive down payment is better than keeping that $ while it makes more money for you? With how low interest rates are, and don't forget the 0% deals, it is not the end of the world to do the longer term for those that keep cars that long.Even if vehicles are lasting longer, long-term notes don't make sense when little is put down, and the new owner is instantly upside-down the moment they drive off the lot. One accident (auto or medical that leads to loss of the ability to work) or downturn in economy leading to a job loss puts the owner in a bad financial situation. The probability of something like that happening increases when you're paying on a vehicles for 6-7 years versus 2-4 years.
These long-term financing options are making people think just the way you are stating it. It'd be the same as saying that it would be wise for mortgage lenders to make 45 year notes an option to the public so people can afford more house than they can truly afford.
We saw the pop on the housing market, I feel the same will come with auto loans. If that's the case, I'll be looking for a good deal on repossessed vehicles here in a few years.