Google has an interesting time lapse progression that shows how development of Westwood Plateau swallowed up our old Westwood race track. https://earthengine.google.com/timelapse/
I've tried to zero in on what appears to be the last vestiges of what was Turn 3 in Google Earth and it looks like the top edge of a gravel pit has encroached on it.
The only thing you can still see is the last little bit of the run up to Deer's leap. The screen grab is Deer's leap in 2017. The last time I was on this piece of the earth I was on the back wheel at well over 100 MPH Sigh!