I have an '02 EX-L. From day 1, I've noticed a tapping sound coming from underneath the vehicle as if from the gas tank after I've parked and turned off the motor. It sounds like a tap on plastic which occurs about every 10-15 seconds. I'm familiar with the usual cooling off sounds of the exhaust components that have a tinny sound, but these continue long after those stop. I don't notice it in the morning after it sits for quite some time. Just wondering if anyone else has experienced this and what it could be.