Wont Start, Dies, Help ! 1995 GT-5.0

[Year2001Boogie]

Someone please help!

I have had this problem for years & the dealership thinks Im crazy!

I have a 1995 GT Mustang V-8 5.0 (only owner, myself)
The problem I started having was about 3 years ago, when I turn on the car, it wouldnt start, it keeps going like it wants to turnover but nothing happens, one day it didnt start so I put it in "N" to push it, got in & started fine, (this doesnt happen all the time but now I would say one out of every ten times I try to start the car this happens), so when ever the car doesnt want to start, I put it in "N" and it starts right away, now the additional problem I am having, is that it now also just all of the sudden turns of while I'm driving, and the the problem happens where the car wont start, sounds like it, will but just never gets to that point of being ON!
Does anyone know anything about this?
Any suggestions?

I have changed or the dealership had changed the following,
battery, alternator, battery cables & ends
fuel filter, fuel line, starter, distributor cap, distributor wire, spark plugs, some re-lay switch thats unknown to me, plus a few other things that I cant recall right now