Let us start with ease of obtaining.

A friend of mine still has a 1975 Pontiac Lemans.

To obtain parts for this car he has to literally go to junk yards and even online.

No new car dealers keep parts beyond 10 years or so and even auto parts stores limit their inventory to cars under 20 years.

It may not look like a brand new piece, but it will definitely be worth the money you are paying for, with repairs and all.

"Pick a part" type auto parts businesses tend to work with salvage and insurance companies to get choice wrecks, and while you probably wouldn't go there to get an RX-7 door panel, they are perfect spots to find interior RX-7 parts and engine parts.