why wont my 2003 pontiac grand am gt stay running

just like so many other grand Am's.it starts and runs for a while then after
so long it dont even start.  It appears to me that this is the nature of all of
them.  When it starts acting up of dying all the time pretty soon they wont
even start.  Im sure that any mechanic that works on these cars will know
whats up.  Sounds like to me the problem is so wide that you have to
check out numerous things before you can find out what it is.