or not, but WATKINS GLEN and SEARS POINT work in the icr2 demo.
I've driven around both of them with other cars on the track.
I haven't tested the other tracks but assume they work also.
Here's what I did:
1) copy all the files from the \nascar\tracks\<track>\ directory
to a \icr2\track\<track>\ directory for the track that you
want to drive on.
2) Use the icr2edit.exe program to change your damage option
to NONE.
3) Start indycar and go the the race menu. Highlight the "Laguna"
button first and wait for the picture to load.* Then you can
highlight the nascar track you want to drive on and enter the
track menu.
* It's important to highlight the laguna track first, otherwise,
the nascar track won't load!
4) On the two nascar road courses, I came up outside the track
walls. If you didn't set the damage to none then the car
will explode when you try to drive through the wall.
One odd thing I noticed is that the other cars seem to drive around
the track at the same speed that the nascars did. I think that by
editing the track files this could be changed. The pit line in the
<track>.txt file could probably also be hacked into putting you and
the other cars into the pit lane of the nascar track. Then damage
could be turned back on.
Good Luck!