dry install the bows by themselves .keep them pointing straight up.draw a diagram . uusally a rectangle box with lines representing sections.label a,b,c,d,e,f (6 bows) write down the distances. eg: a-b,b-c,c-d,d-e ,e-f f-g.get a tape measure and measure the distances in the centre of the bows.write them down. now those are what the panel sizes should be. now measure your headliner yu have by laying flat good side up.measure between the seams.if you pretty well off you have the wrong headliner.hope this helps.