hard starting when wet
 

my 2002 C230K Coupe, 55,000 miles, is starting to have difficulty starting, mostly when wet. My first thought was ignition wires, but I'm told this car has 4 coils and 4 connectors in lieu of typical ignition wires. My (indy) mechanic is guessing it's the connectors, not the coils, but is there any way to sure, or at least an educated guess?