Earlier quoted context omitted.
I think there are two things at play here: 1. The US is much larger than the UK, with a lot of nothing/low population density. 2. Mentality might be different: I imported my current car used from the Netherlands; the country is tiny, but the Dutch seem really like driving a lot. I saw many cars with 30k miles per year on them.
Do people in the US really drive to through the country that often? I guess people drive maybe 2000-3000 km a year for holidays, e.g. to skiing resorts in winter or to Italy in summer, but even that isn't average. I'd say most of the drives are commutes to work and shopping.
Now Germany has a population density of 621 people/mi². The US has a little less than 100. Assuming similar interconnectness (family, friends, jobs, holidays), travel distances are much larger.