Spray the silicone spray on a styrofoam coffee cup. If the cup dissolves quickly, this is not something that is safe around plastics or rubber. For long term safety around rubber, use a pure silicone spray or the grease as mentioned above. You would be surprised at the number of silicone sprays that will fail the cup test!
2003 Saturn L 300 121,850 miles
2013 VW Passat TDI SE, 23,500
2014 VW Jetta TDI SportWagen 7450 miles