Firstly in answer to your question on what can you buy with that income? Thats what Purchasing Power Parity means.
I am aware of what PPP is for, thanks. It is however of limited use when comparing the cost of living. We can work out the relative cost of a given commodity and say that it costs more in one place, but that's irrelevant if it's not actually necessary in the other place.
Regarding car ownership 78% of UK households had access to at least one car compared to 92% in the US. However car ownership is significantly cheaper in the US than the UK (fuel, price of vehicle, tax etc). So the average UK household pays more for car ownership than the US.
Americans drive much further (twice as far on average) and usually in less efficient vehicles so end up spending more. According to the Bureau of Transportation Statistics, the average American car costs $12k/year to own, maintain and run. The average British car costs £3.5k ($4.7k) to own/maintain/run per year. Assuming that you even need a car of course, there are 0.85 cars per American, only 0.6 per Brit because Brits are more likely to be living somewhere that going car-free or at least sharing one car with the whole household is a practical option.
But whichever way you cut it the average US citizen is significantly wealthier than the average UK citizen and the US economy has and is growing significantly more than the UK economy.
Of course there is less inequality in wealth in the UK, but on average everyone is relatively poorer. And I think that the main difference is that Brits seem to prefer being poorer so long as someone else doesn't have a lot more money than them.
Money doesn't buy you happiness. It does of course buy a better standard of misery but studies have shown that you'd need three times the income in the US to achieve a comfortable standard of living compared with the UK. Salaries in the US might be better at the top end, but an ASDA shelf stacker is far better off than a Walmart one.