Hi, I’ve recently developed a misfiring problem with my st150 due to water getting into the plugs because there’s nothing covering them as the car is far from standard it has an aftermarket air filter. So I need help with working out how to cover my spark plugs as the standard air box usually covers them but I don’t have it on the car. Thx

Something like this...
https://www.autospecialists.co.uk/produc...-for-mk6-st150/

Water doesn't usually get onto the plugs, unless you've got bonnet vents?