I asked and asked around, this is the best I got.
GPS Church Brothers Collision repair 135 WEST MCcarty. That business along with several others allow parking and there is supposed decent tailgating there. Sounded like a good atmosphere, the woman that gave me the info is a decently motivated Colts fan.
That's the best I can find, and again, I haven't been there, so I don't know the details, but she said it's some good tailgating.
Colts fans are mild, so they would be probably a decent time. Can't promise you anything, but this seemed like the best lead.
Good luck, see you there? If you see the guy with the long striped socks come say hi to JUstRN