re:
Mike,
I have not used the Meguires product, there are however several methods to remove swirl marks. What ever you use remember that you don't need alot of product to do the job. All you need is enough to cloud the paint. Make sure that you start your repair with a clean/new pad if your using a poiisher, low speed. By hand your going to have quite a bit of work to make it appear even. Make sure that your fender is not hot from sitting in the sun or anything like that. You may also want to wash that fender good with some dish soap and water and remove any wax/polishing compound previously put on the fender before you start. Slow is the best way to go with this, also make sure that the products that you use are for clear coat finishes. Sounds like either the wrong product was used or maybe the buffer used had a contaminated pad on it. Good luck