the arguments for the E420 should also apply to the 400E, right? Since they are older, they should be less expensive.
and with the difference in price between the two, you can invest in Bosch Euro-headlamps, and it will do wonders for the looks of the car and performance of the headlamps. And if you have money left, you can purchase 16" 8-hole wheels and wider tires.
the E420 is the prettier of the two, with its more elegant grille and headlamps. <nitpicking>But if someone attempts to steal your star, they can scratch the paint on the hood </nitpicking>