What is this part called?

[Spencer2001]

I replaced the bushings on the seats last weekend and noticed there is another part that is broken and needs a replacement, but I honestly have no idea what it is called or how to describe it (what can I say, I’m a physician, not a mechanic)…
It is the plastic piece that the carrier slides into, to attach it to the drive motor unit. It also explains why it was juddering when I moved the seat forwards.
I’ve attached photos … once I know the name, I can order a replacement part
Thanks for your help!

 

[DomiMik]

According to RealOEM this part isn't available separately, you would have to buy the whole seat base. I'm sure one of our brakers will be able to provide help.
@spurs fan in a coupe

 

[spurs fan in a coupe]

Yep, no problem

send me a PM

 

[NZ00Z3]

The juddering can also be cause by the two sides being just a little out of alignment. This is caused by having a different number of turn counts on each side when you in the nut block.

I've found 9 turns on each side works well.