I have a RX400h Executive imported from the US. The previous owner here in Sweden converted the sat-nav to an european one (I have been told it was very expensive). Lexusdealer here replaced the radio to european standard and put in an Ipod Interface in the glove compartment at no extra cost.
But fact is - even though the sat-nav is fully replaced, fuel consumption, distance travelled, temperature etc are still in US miles/gallon. Lexus here say they don´t know why.
Well I´m used to it now, I have learned what Fahrenheit is to Celsius and what the average fuelconsuption 24 US Miles/gallon is. I got it for a very good price and love the car :D
Good Luck