Google Ketchup You'll probably want blender too, it's handy for importing/exporting .dae files (and if you have wizard hands, it can be used for modeling) If you are going to use ketchup, make sure you know what you're doing. An extruded profile of a car with lines drawn on it does not constitute as a car. don't do dis ^^^ do dis ^^^ 3DS Max is also popular for modeling, and very powerful software. on the downside, it costs money...
If you've used 3DS Max before you might find Blender aweful. But if you are new to modelling you should learn Blender. Because it is free and has lots of tutorials.
You do know that is exactly the same as what you do in Blender. Polygonal modelling is what it is. Sketchup is only holding you back. I also suggest blender, especially for faster modelling. The shortcut keys make everything really quick. Things like Maya and afaik 3ds max are all menus so it is slugish as hell from my experience. Not to mention the cost.
Sketchup is a good primer to basic 3D modeling, and works well for some applications (such as architecture.) I'd recommend it to new 3D users trying to get a grasp on the basics, but it is by no means a good platform for advanced work (such as BeamNG vehicle models.) Blender, on the other hand, does everything you could possibly imagine, and a few things you couldn't, at the cost of a steep learning curve. 3DS Max also works, however it has a price tag of several thousand US dollars (unless you were to pirate it, like a naughty person), and isn't any more technically capable than Blender, though it offers an easier user experience for less advanced modelers. In short, for new modelers wanting to make cars, get Blender, then mash tutorial videos into your eyeballs until you know how to press at least a few of its nigh-infinite buttons.