As well as comparing prices with other European countries, we compared the prices of cars in the UK with those in the US.
It's unlikely that anyone would import a left-hand-drive new car from the US, unless it was a distinctive model that isn't sold in the UK. Even so, we wanted to see what life was like on the other side of the pond.
A Toyota Prius sells for 10,710 in the US compared with 14,623 in the UK, a saving of 3913 or 27%.
Not bothered about being green? Then how about a long-wheelbase Mercedes S500? In the US, it's 36% cheaper before tax: 39,611 compared with 62,128 in the UK.
The saving on a BMW X5 is 38%, or 12,557 on the UK list price. In the US, it's 20,762.
The biggest percentage disparity of the four cars we looked at, though, was on a Volkswagen Golf GTI at 39%.
The US pre-tax price is 10,322 6767 less than in the UK.
We asked VW how cars can be so much cheaper in the US.
A spokesman said: 'In relative terms, the prices of the two vehicles are similar due, in part, to the weakness of the US dollar. In addition, the GTI needs to be competitive with vehicles built for the domestic market. This is simply the reality of the challenges that face European companies.'