European cars, like audi and BMW use a stud lug that is 14mmx1.50.  This is what I'm using to replace the lower ball joint bolt.  I coulnt find a hardware shop that stocked anything, then I checked  lug nuts and it much easer to get and pending how patient the guy behind the parts counter is, you'll be able to find the length you need.  I think I ended up with an old A4 lug