I used PL Premium construction adhesive to glue mine back down (mine were not completely off, just the ends lifted up) Stuff works on EVERYTHING.
The knockoffs (like liquid nails) don't work, but PL is flawless every time and impervious to road salt, chemicals and oil/gasoline. Bonds wood, metal, concrete, plastic, some foams, etc.
Don't get any on your skin, you will not get it off for 2-3 weeks.
Been rock solid for almost a year, and the worst winter in 5 hasn't touched them.