I used the DynaPro on my interior floor on a few different trucks, seems to hold up well for that but not sure how it would do on a bumper, probably fine. Just re-spray over any rock rash. I really like how well it covers and that sh*t will stick to anything! Wear old clothes eye protection and at least a particle mask when you spray it it is HEAVT DUTY on the noxious factor!!!! its like $8 a can at my local auto body supplier here but worth it and I always have a can on hand