Peter,

The car in question sat for a few months in SF before I came upon it. It was filled at the same very busy Rotten Robbie station my 81 SD and SDL are filled. Those cars never had an algae problem. Come to think of it, the 81 SD sat for a few months in San Jose with a sheared flex plate before I came upon it.

Sixto
95 S420
87 300SDL