I've currently developing a brand new insim addon now I've got to the point where I'm stuck, I'm familiar with using nodes for stuff like street names now I need to use the x and y as the open config tracks don't support nodes, I've created locations around the map based on distance from the x and y point but this just isn't feasible for what I want. Now I've tried using the LFS 2d polygon drawing tool here on the forum, it outputs the coordinates for me but doesn't tell which are x or y and how would I check if a car is in the polygon when I starting messing with mines values it confuses the hell out of me if anyone can could help that would be great

Simple and kind of hacky example.
You'll probably want to take just the algorithm in Area::contains().

Im using C# and Insim.net btw

It really doesn't matter what you use, all you need is the algorithm that checks whether a polygon contains a given point. Writing the plumbing code around it what will let you define polygons should be relatively easy...

Its okay I got it working using the algorithm you gave me works great!