actually Kev, it's 17", and it shouldn't matter if the mount points are closer together than you are wide
and you can attach them to the floor in "pairs" so you only have 4 bolts if you add a stout plate under for stiffening
Dan - I've never heard of anyplace 4 on a bench is legal, but I can't imagine how you could fit 4 across in a TF seat anyway and still have manuvering room for the driver unless 3 are wee kids .... if you have a small window cab the shoulder belts are workable, but I wouldn't try it with a big window
Bill
