S4 battery replacement suggestions?

["Timothy A. Wicks" <75052.1503@compuserve.com>]

I need to replace the battery in my '92 S4.  It's the type that is under the
rear seat, it has a small black plastic "protector flap" that snaps into the
battery near the positive terminal to protect from a short with any of the seat
hardware, and it has a small ventilation hose coming out of one side.

Must I replace this battery with an AUDI battery that has all the same features,
or can I buy an "off the shelf" one as long as I at least protect the positive
terminal???
Any suggestions??
TIA
Tim