Among the cultured elite, art has been the most widely watched and talked about collectible in recent years. But it's the good old automobile that has been a better investment.

According to the Knight Frank Wealth Report, classic cars were the top performing collectible investment in 2014, posting gains of 16 percent. That narrowly beat art, with 15 percent gains, and coins, with 13 percent gains. But cars left stamps, jewelry, wine, colored diamonds and watches in the dust.