What's the problem, Mr. and Mrs. Average Investor? You say you're soured on stocks? Bonds give you the blues? Mutual funds make you mutter?

No problem, says Rick Cole. Just turn to the classifieds, find yourself a nice little '65 Mustang convertible and snap it up before someone else does. Then sit back and wait for it to go up in value.Even if it doesn't, you can have fun waxing it on Saturday afternoon and driving it to church on Sunday (In nice weather, of course. It wouldn't do to take your retirement fund out in the rain.)

According to Cole, president of Rick Cole Auctions, the largest collector car auction on the West Coast, the interest in "tangible" investments, such as collectible cars, has been rising this year, no doubt partly due to last October's stock market crash and the aftershocks that have made many investors leary of traditional markets.

Also, says Cole, foreign collectors have "discovered" American collectible cars and have been attending auto auctions with fistfuls of (devalued) dollars and a never-say-die attitude.

The result, not surprisingly, has meant rising demand and rising prices.

But some cars have been rising more than others - a lot more. If you had a '49 DeSoto four-door when you were a kid, you may have a soft spot in your heart for them but that doesn't mean anyone else does.

Thus, Cole has assembled his 1988 "Gold List" - an index of the top 10 collectible cars that have been enjoying, and he believes will continue to enjoy, the largest gains in value.

However, old cars have one thing in common with stocks and bonds: there are no guarantees they will make you rich, or even return your original investment. (They may, however, make your mechanic rich.)

Bear in mind, stresses Cole - who first predicted the Mustang convertible's rise to collector stardom a decade ago - that these are not "antique" cars; the old and rare marques that millionaires like Reggie Jackson collect. These are cars that Cole describes as "affordable" collectibles, some of which are still available for a few thousand dollars.

Cole also advises novice car collectors that the best investment is always the car in the best possible condition. The cost of restoration can easily turn a bargain into a bad buy.

All right, here's Cole's "Gold List" along with a few of his comments on the cars:

- 1964-68 Pontiac convertibles: "Still going up in value."

- 1965-67 Jaguar XKE roadsters: "Europeans are buying these up in droves."

- 1967 Corvette 427 with 435 horsepower; both coupes and roadsters. "Only a few of these available at any sensible price."

- 1963-64 Cadillac convertibles: "Worth three times the asking price in some cases."

- 1965-67 Shelby Cobras: "A GT 350 or GT 500 is now a target for serious collectors."

- 1961-63 Chrysler 300 "letter" cars: "For the sophisticated collector who knows how the car can perform."

- 1970-71 Barracudas: "Powerful performance made this car light years ahead of its time."

- 1955-57 Chevy Bel Air hardtops and convertibles: "Fifties nostalgia is still going strong."

- 1964-68 Mercedes-Benz 230 SL and 250 SL roadsters: "Cheap chic and a bargain under $10,000."