Technical Brownish - Red Metallic paint?

I don't think I'll be custom mixing. I do have some 1966 Cadillac Autumn Rust which is a very slight reddish-brown. It would have to be lightened and have some red added. I think I'll just go with the VW Cardinal Red metallic. So far it's the closest as far as I can see. I'll try and look at some color chip books to see if it's the color I want.