http://www.nytimes.com/2007/10/28/automobiles/collectibles/28WORST.html?_r=1&ref=collectibles&oref=slogin for the full article, good reading.
1963-64 STUDEBAKER AVANTI
1976 CADILLAC ELDORADO CONVERTIBLE
1975-76 CHEVROLET COSWORTH VEGA
1975-76 BRICKLIN SV-1
1981-82 DELOREAN DMC-12
1985-91 FERRARI TESTAROSSA
1988 35TH ANNIVERSARY CHEVROLET CORVETTE
1982-91 PORSCHE 944
No surprises for me in this list. Late 70's and early 80's cars as collectibles? Not such a good idea. With the very rare exception, late 70's and early 80's weren't very desireable cars, or bikes, or trucks. But it seems that there must have been a big enough demand for these as collectibles that the NY Times wrote the article... wouldn't a better subject be the collectibles that really paid out huge?