Factory Oil pan drain plug question

[Little6pack]

My 86 GN had a metal bolt head you use a socket on this drain plug.

My 87 Limited T has a plastic oil drain plug with alan wrench insert?
The prior owner said he bought this plastic plug at dealer as a replacment to the original style. IS THIS TRUE?

 

[Grumpy]

not that I have ever seen on a Buick .. TTAs has one like you are talking but its not "plastic"

 

[Little6pack]

It was dark when I was looking at it maybe it is metal & from a TTA