I've been told that plastic 'rim protectors' will give excellent protection against any kerbing risks of my alloy wheels, and if I want to keep the existing look of the alloys, they can seem almost invisible. I've looked online and there seems to be a 'stick on' type and one where the tyre needs to be deflated. Has anyone tested or used these? and are they effective, or is using them only going to ruin the look?