In my situation, I try Teflon due to one reason. I had been a DIY guys for many year. I even like to DIY sound proofing and stuff. Currently, I only have silver colour car park at home and go outstation everyweek. After polish, clay , wax etc etc..if I park my car outside for 5-7 days without washing, my car will tend to turn into darker colour and sometimes in patches.. From what I found out, this is due to the reason wax absorb or melt under hot sun and all the dirts or stain will stay in between the clear coat and wax. If this is the case, I need to wash it like once or twice a week in order to maintain the clean and clear of patches. Prolly after 4-6 mths, I can redo the detailing process again.. If I miss out the washing part in 5-7 days, or maybe wash it in day 10, the dirt and patches will be there until I detail it the next time...
I tried out teflon for about a year and I sent my car for chemical wash in between 6-7 mths. However, the paint will be clear, clean and bright instead of with dirt and patches. I send for chemical cleaning bcoz the paint is not smooth and water beading is not as good as new..So, even I park my car under the sun for 3 weeks without driving, come home from outstation and wash the car, it will still be good...At the end of the day, it will be very easy to maintain for me..On the shine and gloss, I think some of the product out there is better but it is not long lasting as it is... I tried many brands b4 this..

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So, teflon to me is like a coating which help me to maintain and clean easier. Besides that, I never had a tar which is stick to my car or hard to clean off. Even after some long journey especially to Trgn, the Karak path is forever ROAD PATCHING, there will be tar marks all over but after 2 days or so when I wash my car, rinse it with pressure gun, apply shampoo and then it is good to go..No need to buff or use any special polish to get rid of it...

My 2 lingam cents oniiiii after about a year of Teflon user...

Cheers