lug nuts made for an atv will work
Just go to a motorcycle/atv shop and get a few sizes and go outside and try them on the car till you find one that works. They are much cheaper than the oddball size that napa can get and are in stock pretty much anywhere. I am pretty sure they are 10mm but I don't know the thread pitch. The atv lug nuts have much wider shoulders so they mount up 13 or 14 inch rims just fine. It is also much easier than drilling the holes out for larger studs.
btw if you don't mind going to a 14 inch wheel the
90-96 honda accord has 14x6 that fit the car just fine.