you have to really try to do damage, the distributor has a gasket on cap and unless fooled with it should be water tight, i still steer away from soaking it, the plugs can get a little hairy, i got some water around the plug boot and filled the plug ports full of water, she ran like it was loosing fuel do to the insufficent spark, i wash mine at the car wash and go for it, as long as it's not a paper air filter and you dont hold it directly on the filter it'll be fine. there are cai systems that use a water drip solution to cool intake air. the brake and clutch res's are fine almost imposible to get moisture in them, the only thing that worries me is harsh cleaners on stainless or chrome surfaces, i use car wash to hose oil / heavy dirt off and then go to town with armoral on everything, it will shine everything.