Jerry, I had the same problem with my ports and hatches and proceeded to clear them all last summer. The T-10.5 has a pilot house which was useless with the hail lines on all 20 year old ports. As you did, I tried the MEGUIRES products without significant results. I also wet sanded some of them with no 5000 paper; I saw improvement but nothing to write home about. Finally, I used the NOVUS products. I understand that this is what they use to polish LEXAN bullit proof glass in police cars. Used with a buffer, these products did remove most of the hair lines and restored the ports and hatches to a useful level. These is 2 kinds of compound, depending on the scratches. There is also a polisher to protect from oxydation. For nearest distributor, call 800 548-6872 Good luck Bert.
