First of all: With the kind help from Holemad, Zieli, Claudio and others I have uploaded a couple of new and some re-worked conversions from GP2...
New circuits:
San José streets, California. Used for ChampCar series 2005-07
Houston Reliant Park, Texas. Used in 2013-14 by IndyCar series. Unfortunately not on the 2015 calendar, but hope to return later.
Re-worked circuits:
Miller Motorsport Park updated with more objects, more authentic fencing and adverts/sponsors from IndyCar series.
Lime Rock Park updated with more objects, more authentic fencing and adverts/sponsors from IndyCar series.
Sao Paulo streets, Brazil updated with more objects, work on pitlane/grandstands and adverts/sponsors from IndyCar series.
Tracks still need more work from a more skilled 'modder' but they are drivable as they are for the moment and looks okay from cockpit when driving.
Available from download section "Cart and other tracks" ....