Getting a little tired of misfire issues on this thing.

2008 Grand Prix
3.8L engine

At various times I have replaced all three coils the module they plug into. Daughter just called me said it was shaky when she started it.

Is the coils and module that prone to failure, it seems like every 6 months to a year I am replacing them

I am assuming with the P0305 it is the coil for cylinder #5, is this everyone else's prognosis?

I need some quick help as I need to drive 2 hours to work on it.

Thoughts?

Thanks,
John