Tracks:
North America:
Watkins Glen
Mid-Ohio, Lexington, Ohio
SCCA Solo (Autocross Nationals), Topeka, Kansas (with a dozen or so tracks, or design-your-own)
BeaveRun, Wampum, Pennsylvania
Indianapolis Motorspeedway, Indianapolis, Indiana
Road America, Elkhart Lake, Wisconsin
Sebring, Florida
Circuit Gilles Villeneuve, Montreal, Canada
Pacific Place, Vancouver, Canada
Apodaca, Monterrey, Mexico
Mexico City, Mexico
South America:
San Martin, Mendoza, Argentina
Buenos Aires, Argentina
Interlagos, Sao Paulo, Brazil
Autodrome Ayrton Senna, Caruaru, Brazil
Europe:
A-1 Ring, Austria
Spa-Francorchamps, Belgium
Magny-Cours, France
Reims, France
Hockenheim, Germany
AVUS, Germany
Oschlersleben, Germany
Imola, Italy
Monza, Italy
Zandvoort, Netherlands
Moscow Ring, Russia
Catalunya, Spain
Jerez, Spain
Jarama, Spain
Gotland Ring, Sweden
Brands Hatch, UK
Donington Park, UK
Manx TT, UK (they raced cars there once upon a time)
Silverstone, UK
Australia:
Albert Park
Bathurst
Surfer's Paradise
Africa:
Killarney, South Africa
Kyalami, South Africa
Midvaal, South Africa
Asia:
I don't think that they should get any until the U.S. and Europe are more equally represented. The majority of significant motorsports history took place in Europe, and the U.S. has more racing tracks that any other nation, yet there are only 2 real U.S. circuits and 3 European, and 8 tracks from Japan Exclusively!
Obviosly there is no hope that all of these would ever make it, but 4-5 from NA and another 4-5 from Europe ought to be resonable.