The following tracks shown in your queue are at this moment viewable in google earth, sometimes not by default but they are shown.
Bahrain international Circuit: now shown in it's latest configuration. Original layout viewable using time travel option (that clock in the top toolbar).
Road America: already done.
Suzuka Circuit: clouds still visible on default picture but not on older picture viewable with time travel option. Dont bother about tracks north of the main straight, slow casio triangle (final chicane) and chicane succeding the hairpin are used for motorcycles.
Homestead-Miami Speedway Image quality up to standards. Tracks used: full oval, full roadcourse and first part of roadcourse combined with turns 3 and 4.
Yas Marina Circuit: track still partialy under construction but you should be able to make out where what it's like.