5 point harness in a car w/o roll cage...How to do it?

BJS racing said
The only reason I put the upper belts in is because they gave me a ticket for not having a shoulder belt in the car.

What kind of #@$#&(%#@ cop gave you a ticket for that? You should have fought that one. Did your car originally have shoulder belts? I do not know of any state that has required reto-fitting shoulder belts into an older car that did not come with them. Unless your car is from the later half of the 70's when shoulder belts became common, or if the cop looked and saw that they had been removed, they would have to take your word for it that it never had them.