You mean the top of the dash? Gonna be tough to get an even finish no matter what. I think my Duster is a little deeper angle than yours. I had the dash out to paint. Hope you have a good respirator. I'm chokeing on fumes just thinking about spraying inside a car. :eek:
The flat finish will make it a little more forgiving, but generally metallic are sprayed. Even then they can be tough to keep even. The metallic will float different in a dry spray than a wet spray and you get stripes. Did some of that on my hood and deck lid.