Hi
I have to agree with Ryaans personally I wouldn't touch t cut on Lexus paint. when i first had my Lexus and before I was heavily into detailing I used t cut to remove a fine scratch, great I thought. got up in the Morning and the sun was shining on the car, the t cut had caused lots of fine maring in the paint, looked awful.
That's my advice anyway, give your maguairs stuff ago in a place that's not obvious first.
cheers