I just recently got the Nismo style ground effects for my car and realized that the side skirts don't exactly fit really great, on the inside of the door where the clips on side skirt meet the frame of the door the new side skirt comes up short. Would it be easiest just to pop-rivet inside the door and just use the stock bolt locations on the bottom of the car

 

you have any pics?

 

a lot of skirts dont look like they fir right. you got to bolt the bottom and then brute force align the tops. my greddy's were like this but ened up working out

 

You may just want to head to a good body shop and have them take care of it. A good shop can turn junk into gold.