Oops meant to say "drain" hose in thread title.

So ... Installed the IBS system from Wakemakers over the weekend and noticed that the drain hose is connected to the top of the bag. It drains fine but is that normal? Seems weird to me to have a drain on the top of the bag.

The problem I have with it is when it is full, the 90 degree elbow on the drain hose prevents the front seat from sitting flush.

Any ideas?