What can be done for those who are very tall and also need to accommodate short people is this (I did this for a friend a few years back).

I essentially did the same as shown in the attached pictures but in a slightly different manner. I took an extra set of seat tracks, cut out a 6" section from each and welded in on the back so the seat could go 6" further back than original. This was carefully but-welded. I had to cut a few notches for the locks to slip in to and remove the stop (bent tab on the track) to allow the extra rear movement, but the studs were left in place so no new holes were put in the carpet or floors. The seat springs (return to forward springs not the lock springs) were worn out enough and my friend is strong enough to easily put the seat all the way back.

______________________________________
Laziness is the mother of invention. :-)