I'd recommend Poorboy's BnB or Zaino Z16 for smooth fender liners and most textured trim. I'm also a big fan of Poorboy's NL and Trim Restorer.
Z16 is just ridiculous - I love it. And for a coupla' years there I figured there was nothing better than BnB. The flexibility between matte, gloss, and wet is very easy to dial-in on black trim as well as tire sidewalls.
VRT, to my tastes, is just too glossy and the durability is horrible. I received a sample of Adam's undercarriage spray, and have mixed feelings about it. For heavily textured wheel wells - a la Lexus ES - it's great because it just covers everything. But it also leaves everything really wet looking. If this is your preference, you might really like it. The odor (too sickeningly sweet to call it a scent

) is really strong too. Your customer may wonder where you spilled the grape soda.
Anyway, for me, unless the wheel well is too textured to apply it, my favorite is Z16 with BnB still on the shelf for backup duty. For the heavily textured fender linings, I think I actually prefer the old staple...Armor All. For weatherstripping and other trim, the PB stuff - NL and TR - is outstanding.