remote windows, doors

I am buiklding a 1934 Ford pickup streetrod with (of course) all the modern amenities.  It has shaved doors (no handles) and will use a remote transciever for opening the doors.

In addition to the doors, I would like to be able to open/close both windows with the remote.  I have install instructions for doing this in conjunction with the manual switch for each window.  It has two relays for each window--one for opening and one for closing.

This is all straightforward enough but, I want to modify the design a bit and don't know how to achieve what I want to do.

I want to be able to control each window independently using the manual five-wire switches (no problem, witing harness included with window kit).  I want to control both windows at the same time (not independently) using the remote.

I know I can easily connect both windows to pin 30 of the relays so that both work together with the remote (as long as I use a large enough fuse).  Where I am lost, however, is how to include the five-wire switches in the mix so they can control the windows independently.  If I just wire the switches as if the remote (thus the relays) doesn't exist, will that produce feedback to the relays and cause damage/unpredictable results?

Summary...I want to have only two relays, one to open and one to close both windows at the same time with the remote.  I also want to be able to use the manual five-wire switches to open/close each window.  Can this be done and how?

Wow, that image sure distorted!

It is a standard five-wire, reversing diagram.

Well, for starters, I already have a SPAL control unit for the door openers that I can't (don't want to) replace, so how would the 530t work into the equation?

The diagram is a bit fuzzy...power goes to 85 on the first relay (up) and 86 on the second (down).  The remote trigger goes to 86 on the first relay (up) and 85 on the second (down).  In a "normal" installation this would be repeated on two additional channels for the other window.

What I'm trying to do is use one channel to open both windows and another to close both while keeping the manual switch for each window.

Maybe this diagram will help illustrate what I'm trying to do...

Okay, here is the diagram SPAL tech support sent that does what I want without the need for any additional modules of any kind.  Thanks for the suggestions.