According to Spanish auto trade association ANFAC Spanish car sales plummeted 24.3% year-on-year to 116,108 units in May.

The cumulative figure for the first five months was 587,407 units - 14.3% off last year's pace.

"Until now, the problem of expensive fuel has not had an immediate effect (but) when you add the fact there's more unemployment, financing is more difficult and it's obvious that interest rates are high, well, the rise in fuel prices hardly helps," ANFAC Director General Luis Valero told Reuters.

The Ford Focus was the top selling car between January and May, ANFAC said, followed by the Citroen C4, the Renault Megane and Peugeot's 207.

Spain's economy is suffering this year on the back of a troubled property sector and fragile consumer confidence.

"The continuing deterioration of the economic situation, coupled with a clear slowdown in consumption, increased unemployment and inflation and tougher credit conditions explain the important market drop so far this year," ANFAC said.