The bulb specs in CX-5‘s owner’s manual is wrong for rear turn signals. It says WY21W (7443NA) but it should be single-filament 7440NA as 7443 is a dual-filament bulb、and NA is “natural amber”. So I’m not sure how the LASFIT 7443 can fit into a single-filament bulb socket?
For your 2014 CX-5 it has 1157NA but for 2016 and newer CX-5’s they have 7444NA on front turn signals. Since both front turn signals use dual-filament bulbs and do you use “switch-back” LEDs? (white / amber, and amber-bright / off and amber-bright / off during turn signal mode). What kind of front turn-signal LEDs do you have?
I believe the T-tap connectors you found are for trailer lightings.
Added oem black mirror caps to my white 17. These are not just plain black. They match the black oem paint so there are metallic flakes in it. Just popped off the old cap and slapped these in. Took 10 minutes.