I have a 1985 camaro iroc z28 5 sp wiyh a w as the 11th digit in my vin did they build the camaro at that plant ?

You don't believe it'* a Camaro????
You think the VID is wrong?

Best I can find is:

N=Norwood, OH
L=Van Nuys, CA

Looking at it from the other side, Willow run was building the following platforms in/near 1985:

X-body
H-body
B-body

I can't find any evidence that any F-bodies were assembled there near the time your car was built.

The next question is: How does your 1985 Camaro have a "W" in the 11th position?

I don't see anything that tells me that your car should have a "W" in any position in the VIN.