Originally Posted by enzeru
with 1.8 aperture will likely to give you bokeh background and also will be difficult to focus the whole car. Anyway, it really depends on how you want it though...
this isn't a helpfull comment as a 1.8 aperature is only one of many aperature settings can be used, not just one, so i'm not sure how your comment applys.
a 1.8 can shoot at F22 for all it matters and have no bokeh in the picture at all, and that's why i recommended shooting at 2.8 or 3.2 to get the car in focus, but keep the background a little out of focus.
OP, also shoot all the way through to about F8 or F11 to get some background in focus if you have a nice background, but no matter what aperature setting you use, you'll get best colour and contrast with the 50mm prime.
go have fun, and don't worry about your equipment too much, it's all about learning from now, and one day you'll get your skills to where you want them to be with practice.
next step is post processing like was mentioned by oneintheory.