Cause identified. As suspected, the shiny white vinyl fence post was the culprit. Wrapped both in cardboard and could not cause the cross-traffic to go off while backing in. I suppose the wife will not go for scrap cardboard staying wrapped to the posts with blue painter's tape so I'll have to come up with a more creative approach to knocking the shine off them. It's a new fence for us and I seem to remember someone explaining how to remove the shine using bleach, but I can't find any supporting info on the net. It was explained the shine comes from the extrusion process. The extrusion equipment is lubricated with a product that is essentially Armor-All. It wouldn't be great for the environment to bleach the whole entire fence around the property, but I could hit up just the two posts. There may be other options too, I'll need to look into it more.
So cause found, no solution yet. I'll let the Moderator decide if this gets closed. The solution may be more appropriate for a different forum. If it stays open, I'll return with what ended up working to knock the shine off. Probably won't be until spring. I'm staying away from paint, doesn't adhere well to vinyl and would require frequent touch-ups. I thought of clear frosted static window clings, but they're not meant for exterior use and probably wouldn't stand up to New England seasons. Bleach or sanding with fine grit would probably do it, but they are destructive and irreversible so if I mess it up, I'll be lucky to sleep in the garage. I'll see if I can find some scrap fencing to work with and test some ideas. As long as this thread is open, I'll take any other suggestions as well...
So cause found, no solution yet. I'll let the Moderator decide if this gets closed. The solution may be more appropriate for a different forum. If it stays open, I'll return with what ended up working to knock the shine off. Probably won't be until spring. I'm staying away from paint, doesn't adhere well to vinyl and would require frequent touch-ups. I thought of clear frosted static window clings, but they're not meant for exterior use and probably wouldn't stand up to New England seasons. Bleach or sanding with fine grit would probably do it, but they are destructive and irreversible so if I mess it up, I'll be lucky to sleep in the garage. I'll see if I can find some scrap fencing to work with and test some ideas. As long as this thread is open, I'll take any other suggestions as well...