What exactly has to be removed from the engine to access the rear (firewall side) spark plugs. Looks like intake manifold plenum and EGR valve has to be removed to me.
Spark plug access on 2007 Ford Five Hundred
You are correct, you should get an intake seal kit too. You will have to remove the bar that goes between the strut towers as well as the torque maunt that is on top.
acess to spark plug remove plantium