Wow, I thought I was spending waaaaay too much time on GT5, but I only have 30,479.3 miles (49,051.679 km). I presume by the time I've grinded enough to buy all the premiums, this will have gone up a bit more... I worked it out at something like 110 million required to buy the ones I haven't got, which is roughly way too many laps of Indy. Thank god for the seasonal events!
I've just started my first 24hr race on B-Spec so my miles will go up quickly. As you can see an interesting stat is I have as many cars as I have wins. Just noticed this as I went to check how many miles I had done on both A-Spec and B-Spec.