Amp Rack Construction

I got started on the amp rack. The amp rack is going to be very simple and basic. Because the subs are going to be placed in the trunk in a box, I am not concerned about showing off my amps. I just want the amps to be safe, secure, and accessible. I don't want to mount the amps on the sub box because, the amps need to be more permanent and the subs more as optional. We frequently go on trips where trunk space is needed and the subs have to go, so I want to make the subs removeable and the amps to be permanent. Here are the pics of the beginnings of the amp rack.