2012 reverse lamp socket

I have an issue with my reverse lamp sockets being corroded. I bought some new t15 pigtails and spent the time to cut out the old and wire the new in, only to find out they dont have the same retention clips to hold it into the tail light assembly.

The pigtails are perfect for the tail lamp, but it just doesn't lock into the reverse lamp. Toyota wants to sell me the entire tail light wire harness. Anyone know where to get just a pigtail or a way to fabricate a t15 into this space.