The thing to remember about flexibility, it's a time issue.
All things will harden eventually, it may take 100 yrs, but eventually.
I have had some clears stay flexible for a couple of years then
get brittle, so how much time is enough for a test?
And how much is acceptable?
I usually guarantee my paint for three years. That's what I shoot for.
I have redone some other body shops work that took that long to show up.
Especially blends, where the clear started to show differently.
My own "test" paint job with "Lazer-Dry" looked perfect for 3 yrs,
then went bad quickly.
That's why it's important to remember that just because the paint looks
perfect after being done or a couple of months doesn't mean
it's a really high quality paint job. Time has to pass.
There have been girls and guys on here giving advice about their own high
quality paint jobs and only started painting a year ago. That's not enough.
The real test is time, and for me the three year period seems to reveal
what really has been done.
So if you want to check flexibility or adhesion, I want to see it on
something at least a couple yrs old, then we'll know.