Well it happened. I suspect the screw got there when I was parking at the backyard of a hospital but could catch it in a garage too. Should I remove the screw? Tire pressure monitor is OK and my MINI stayed home couple days. I saw the screw this morning. Any suggestions appreciated. Thank you.

 

Leave it in there and take it to a tire place, see if they can patch it or plug it. If you remove it do it slow, it may not be as long as you think, if you hear air coming out, put it back in. I would not drive on it to long however, eventually it will start to leak if it is not already.

 

Don't remove the screw - it's plugging the hole. You could be lucky - a short screw may not have penetrated the tire, but I'd wait to check that until you're at a place that can repair it if it went all the way through. You don't want to drive it without air, or you'll need to replace it.
That looks very repairable, just take it to a tire shop where they'll remove the tire, remove the screw and patch it. Note that some tire shops won't repair runflats, but someone certainly will.

 

go to harbor freight or northern tool and pick up a DYNAPLUG kit

http://www.dynaplug.com/

read the instructions, load the tool with a plug then remove the screw...if you hear air leaking - plug it. If you don't hear anything spit on the hole and if you see bubbles - plug it. (Use soapy water if you must....) If no sound and no bubbles put the plug back in the tool handle and toss in the glove box for next time.

problem solved - go wash your hands. then check your tire pressure and watch for the next day or so just to be sure....

easist self plug tool I've seen and been using it on both runflats and non for over 5 years. Had a tire with 3 such repairs that ran another year.... good stuff.

 

+1 for Dynaplug. Easy and works. Some larger punctures need you to put a couple of plugs in the hole. But otherwise just about perfect.

 

Great advice! Thank you all gentlemen. The sequence of tire fixing process is perfect. What I did, knowing that a gas station is two blocks from me, using soapy water started to unscrew slowly watching if any bubbles appear. Was ready to put screw back. Fortunately the screw was only 7/16 long. Where it came from I have no clue but looks like a car fastener. Could it come from my MINI ?
That cool tire kit from Dynaplug is on my list to order.