LoganKello

So I found a pair of louvers sitting around my family's machine shed that used to be on my uncles 1990 Trans am...He has no need for them, I went and held the louvers up to the back of my window and its a perfect fit exccept for where the 91 wrap around spoiler begins to wrap...I was wondering if there would be any easy way to modify the louvers to fit? (They are ABS plastic and have no drill hardware)