Hey, so my fiance's sister drives a hyundai elantra and it repeatedly gets misfires in wet or even just damp weather. the spark plugs and wires have been replaced, but the problem is still around.

any ideas?

bad engine grounding. replace all grounds with 4 gauge audio cable and problem solved most likely. i had a few corroded grounds and my alarm wouldnt work when it rained. just look at the negative battery and find the wires. could also be corroded battery terminals/clamps.