Just remember you are clear coating the car twice!! You will have a lot more labor cost with doing a mat finish. The car needs to be cleared like normal with "shinny clear" then sanded flat and cleared with the mat clear.
Also it "WILL" break down over time, with the elements and environment the mat clear does not hold up as good as regular clear coat.
Those high end cars you see with the mat finish do not come with a paint warranty on the mat finish because if you get bird poop or you name it on them you can't just have it buffed out. It has to be repainted or you live with it. The Mercedes Benz has 10 page disclaimer that you sign when you buy the car so you understand what is covered and what is not.
Hope this helps, and I have not painted my car mat but I did stay at a Hoilday Inn last night