Magnetic Sign Work Around Ideas?

Try adhesive putty, shouldn't leave any mark on the paint:

http://www.amazon.com/Removable-Reusable-Non-Toxic-Poster-Putty/dp/B000BQMFEC/ref=sr_1_58?s=office-products&ie=UTF8&qid=1366652538&sr=1-58&keywords=3m+hang

Or gaffer's tape does not leave marks if not left on too long. It's usually blue or black, but here it is in white.

http://www.amazon.com/Hosa-GFT447-Gaffers-Tape-White/dp/B003BVJ7PE


For the airport magnetic light, get this suction cup mount and mount a metal plate to it:

http://www.filmtools.com/cleatsuccamm.html

 

Roadster owners have already dealt with this - static vinyl signs work, it appears. Plenty of info here: Homecoming parades with a Roadster

 

I'm sure those signs will work for other kinds of parades and events, not just homecoming parades. (Perhaps we were a bit too specific at the time.)

 

If you enlarge the pictures, you'll see the vinyl signs on the window of my car. (From last weekend, Fair Park, Dallas). I did have to use a couple of pieces of tape because the wind kept blowing them off.

 

Here are some that work well - 'Joe's Sticky Stuff' - do google search.
and also used 3m wall hanger tape - also google search, but at most stores like target, walmart, etc... You just you the refill tapes.

These work to hold things on at highway speeds but come off clean