[warthog]

Hi Dan,

American spec. tow balls are 1 7/8 inch diam (45.9mm) as opposed to the European 50mm diam.

Therefore, a European socket will fit (but not be secure) on a US spec ball, but a US spec socket will not fit a European ball.

The only way to make your trailer fit your car is to either buy a US spec ball from the States or retro-fit a European socket onto your trailer. There are no adaptors that I'm aware of.

Cheers