yep i'm sure they're not laser scanning infineon, Hockenheim, Indianapolis etc.
also from the same page on fm.net
Xboxygen: How many cars will there be in Forza 5?
Dan Greenawalt: We have not yet provided an exact figure, but there will be many
- Xboxygen: Is there will be more than in Forza 4?
Dan Greenawalt: No, there will be less
- Xboxygen: But all will be available in Autovista mode, right?
Dan Greenawalt: Yes, all cars are available in this mode
Heh, thanks for asking 'more or less' but forgetting to ask if it's "less" as in "150" or "less" as in "450"
Also thanks for not asking if "only old tracks we were not happy with were laser scanned" means all old tracks are included or not