Secret test tracks by Auto Express news

[kach22i]

Secret test tracks
http://www.autoexpress.co.uk/news/autoexpressnews/204239/inside_story_secret_test_tracks.html
Manufacturers don't want you getting near the hidden circuits where they trial their newest cars – but we've dropped in using the latest satellite software...

[HardDrive]

Isn't there a track just west of Chelsea, MI, right off from I-94. I used to hunt out that way, and remember running into rather imposing barbed wire fencing. Locals told me it was a test track.

[kach22i]

Originally posted by HardDrive
Isn't there a track just west of Chelsea, MI, right off from I-94. I used to hunt out that way, and remember running into rather imposing barbed wire fencing. Locals told me it was a test track.

That rings a bell, but I drive the old 911 out that way all the time and don't recall actually seeing it.

There is the old Ford one in Dearborn, the one in Milford, near Brighton - drove past it on the fall color tour, wife had the map.