I carry USP Tac 45 full size IWB, unless I carry G34.
Also carry J Frame in front pocket, but almost
never leave the pistol in the glove box.
I am ca 6'1", medium to slender build & I never have problem feeling comfortrable that I am concealed.
Butt of pistol fits close against my body in small of back on strong side. Also, looking at me square from the front w/o an outer shirt on, you really can't see the slide in my silhouette. It is almost as much SOB carry as hip carry. If I bend over I suppose you can see a bulge, but it is not a pistol outline shaped bulge. Never hand anyone bug me about it. If they did I'd just tell'em its my colostomy bag & to mind their own fuckin business.
I should also point out I live in FL & carry this way year round. I wear button up short sleeve shirts un-tucked, or sometimes golf shirts un-tucked.
I recommend an 8 way universal belt slide holster. I can be carrier on either hip, either in or out of wasteband, & w/ Butt forward or back ward. Sometimes those universal soft universal IWB holsters w/ the slick soft fabric inside work well enough & can accommodate a butt forward position when seated in car
When you sit down in the car, you can pull it out about 1/2 way & then flip the butt forward, put it back in the holster & then slide it forward a little bit so it doesn't dig into you back while seated. Especially if you have side bolsters. Then you can do the reverse when you are getting out of car, w/o even lifting up your shirt. This type of holster generally gives you alot of flexability to adjust for the various conditions you'll be in through out the day.
IMO, w/ hammer down & safety on, mexican carry is fine too as long as you wear cowboy type jeans. But if your pants aren't that tight, you need something to keep it from maybe falling down you pants leg
BTW, thanks for getting your CCW & not being a community security freeloader.