[Mark7]

I had to replace both the black and gray tank in my '04 because of cracks where the lid was glued on. The dealer I ordered the tanks from told me never to travel with a substantial amount of liquid in those tanks. Those tank edges cannot take the pressure bouncing down the highway.

When I replaced them, I did put a strap under each tank to help support the weight until I can dump them.

I always travel with about 4 gallons of water in the black tank, added after I dump for obvious reasons.