Need to see the full picture of the exact situation to get a good idea, however something comes to mind!

The spray in foam idea can be somehow good, not to let it there, but fill all around the wrench ( on bottom better then on top) like a cast, with a wire inserted, then once dried pull out the wire to pull put the cast foam piece build with the wrench in it. The wire needs to be with a bent shape to be sure won't slide off the foam... maybe parallel to the wrench witn several bents.

Some light oil on rocker and quarter panel walls will help the foam to not stick to them.

Maybe sounds crazy but... who knows!