good point there!If it is did you make sure to put some type of barrier between the stainless plate and the aluminum? The two metals definitely don't play nice together and putting them directly against each other is asking to corrode out the aluminum.
that's exactly what i did. some duct tape between (and the inside of the firewall is painted carc) maybe putting a light rubber spacer in.
i also used paint on the hole edges... but yes, that's always a factor.
thought about going in zinc plated, but as everyone knows these two don't play well together either... it's a dilemma...