Issue with the Connect Line Tool

[micheus]

Hi Corey.
Your car looks better then the first one. You are making progress.
I'm not a 3D artist, so what I say here is based on my reading and what I've experienced.

Tip 1: be careful using hard edges. If you intend to smooth your model when you finish take a look at how strange it can look sometimes:
The 3rd image is only to show you the mesh aspect "hidden" in the 2nd when we use Smooth Preview.
For situations like this you usually need to add more edge loops to "anchor/preserve" the mesh. (I never remember the right term for that)

You can make use of Smooth Preview that can help you to identify that as well to see where you need add more edges in order to get the shape more rounded.

Tip 2: Try to create quads face always - avoid tris or ngons (Why Are Ngons and Triangles so Bad?)
It's a good idea learn about the good habits too.


About the space for the wheel...
You probably should have noticed that you will need more edges in order to make it rounded. I'll just show a possibility - you can use the same "idea" and apply to your model until reach the result you are looking for.



It seems you have (again) a problem with the mesh in the rear space for wheel - that extra faces. Here is how to fix it:
Take care about these strange artifact and avoid headache.