auto chocolate
n.— «They sell what are known here as “autos chocolates,” coined because these aging used cars are like a box of chocolates: You never know what you’ll get.…In 2001 the Mexican government offered an amnesty for camionetas chocolates, or imported trucks.» —“Mexico’s changes in laws on used-car imports may open doors for buyers” by Eliza Barclay in San Luis Potosí, Mexico Houston Chronicle (Texas) Oct. 11, 2005. (source: Double-Tongued Dictionary)