That's quite a coincidence! I've got a zzw30 mr2 so that's very good to know.
As for checking if you've got the required plug for the windows, that's actually quite easy. The plastic panel at the bottom of the door jam just pulls off (only held in place by three clips, use a trim removal tool to pry it up) and then the kick panel plastic is only held in with one plastic screw clip. Pop that off and you'll see three plugs with only two occupied. Plugs will be coloured white, blue and grey respectively
Edit: I forgot to mention that this is on the driver's door jam.
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