Those look VERY nice. I kick myself for not using Krylon Fusion when my wife and I painted our flares last summer.
We used Duplicolor's paint for Vinyl and plastic trim. after removing the flares we hit them 3 coats of adhesion promoter, then put 3-4 coats of paint. After it was all done they looked good as new, but I have a few touch up spots from scraping on the trail. the Krylon Fusion probably adheres stronger and last longer.
If I can dig up pics from when we painted the flares I'll post them, but just so you can get an idea.
BEfore when they were faded
and after painted, although a bit dirty in this pic
2001 TJ Sport- 2 inch suspension lift, 31" A/T tires, more upgrades to come.............just because you're small on mods doesn't mean you're not big on wheeling
H2RESQ- The Krylon will come off also. Just ask anyone who has overfilled their gastank a little. Once the gas hits the Krylon it eats it away...
As for prep, I just washed the Jeep, cleaned the flares with an ammonia based cleaner (I used Windex) per the paint can instructions and painted in many thin coats. It has lasted a couple years so far. Mine are due for a touchup though...
i took mine off. washed them with soap and water. took a scotch type rough pad and scuffed them up. just lightly, not like it really needs it anyway, but just in case i missed any dirt.
then just applied a few light coats.