Taillight fit help?

You can always chop the connectors off both car and lamphousing and make splices instead. It's not like they changed voltage or the number of lamps or anything.

 

The OEM taillight has a harness with one connector at one end and 4 at the other for the brake, driving, reverse and signal lights. It looks like the intention of this particular manufacturer was to circumvent the harness and go directly from the light assembly to the single main connector.

That connector is inside the C-pillar, towards the center, behind the sheet metal.

You will need to first unplug the OEM light assembly, dislodge that large, round rubber seal which passes the harness through the sheet metal, then open the plastic panel on the inside of the C-pillar to get to the connector to unplug it. You won't be able to see that connector. You'll just have to work by feel. You will also need to take out the center plastic cover above the spare tire in order to take the C-pillar cover off. The cover is held in place entirely or mostly by clips, but I think there is at least one bolt/screw. You don't have to remove the whole thing. You just need to open up a gap large enough to be able to reach the connector from the other side and unplug it. Installation steps are the same in reverse order.

It's a very simple process, but wear mechanic's gloves and a long-sleeve shirt to save your knuckles and wrists, because the plastic parts are sharp.

I think I posted some pictures on this topic about a year ago, but I can't find it now.