355 Is it normal for plugs to look this bad after two years?

corrosion is due to water intrusion from the cover gaskets not there or not in good shape. If car is exposed to rain or washed with the louvered engine lid water can settle down in the plug holes and you get that corrosion if gaskets are compromised.

Now more importantly the left picture assuming that's all the same bank shows non ideal combustion on that side.. 5.2 OBD car? Fuel trim data would be useful. Any exhaust modifications such as CAT deletes etc?

 

The corrosion as stated is from nonexistent gaskets. Hard to read the plugs with such bad pics that don't really show the insulators, etc. The plugs in the top pic look rich but that may be shadow. Pls post better pics if you want better analysis.

 

Plugs on the right look like mine after 13k miles. Those on the left look pretty bad, especially the first two, counting left to ringht.

 

The gasket does not have to be compromised to get water leak. To totally seal against water, you need silicone or sealant in addition to the gaskets. Even then, I never wash the 355 by dousing it with water over the engine lid, and I never park the car out in the rain for days on end.

 

Ignoring the corrosion, the plugs appear to be rich, and the left 4 appear to be more rich than the right...

 

Those also have rust! How well does a spark plug fire under water? I have no clue but I would not condemn any mixture until I ran the car on dry clean plugs. If the car passes smog it runs well. Smog output is getting tightened up every year.