Since, unlike Singapore, Austin will be a day race, I think you could get by with a superzoom as long as it has a viewfinder. So maybe a Panasonic FZ200 or Canon SX40 or SX50.

I would put those cameras around "McLaren" level performance--yes, you could do better, but the next jump up (Lotus level, i.e. a mirrorless interchangeable lens system camera) would cost significantly more. Not to mention a DSLR (Red Bull level).

HTH - Mark