Painting MDF

I plan on making a ported enclosure for my brahma 15. I have decided i am going to keep it simple and go with MDF. I would like to paint the MDF with car paint to get a nice glossy look. Im not sure what to primer the box with thought. I have heard you can use some type of sealing primer but i can't recall what it was called. Would gelcoating be a possibility? I have no experience with gelcoat but it seems it could be made to work. How hard would gelcoatin be, and what kind of results can i expect from each of the possibly options. Thanks for the help, if this was covered in a past post im sorry in advance, the search function is being a pain. Thanks again.

you can use high build primer, ,first few coats will just sink in, but after a while it will work.2003 Chevy Avalanche,Eclipse CD7000,Morel Elate 5,Adire Extremis,Alpine PDX-4.150, 15" TC-3000, 2 Alpine PDX-1.1000, 470Amp HO Alt.