The vehicle seat

I’m new to garry’s mod and i’ve got so many things to learn but the thing that’s puzzling me most is this vehicle seat,it’s supposed to be under the vehicles section but i don’t see it anywhere,i only have portal 1 and team fortress 2,do i need to get half life 2 for this?

Yes.

Great thanks,i just wanted someone’s else’s word for it!

It’s still not there!Is there something else i’m missing??

What type of seat are you looking for?
Also, have you mounted HL2 in your options list?

I’m looking for the seat that you can sit in so you can attach it vehicle’s and stuff,and how do i do that?