jlinton - I'm also one of those no fruit in my beer, meads and ciders are different. But spices is something else, no personal rules on that yet.
Personally when I add fruits, I like to do it in a bucket to ease cleaning and removing the stuff. I let it hit the target gravity, then add the fruit or spices in primary. Then after 4 days to 2 weeks depending on what I'm adding I rack to secondary.
I have never made an Aussi lager, but I would think a little citrus like one lemon, one orange would add a nice balanced something something. Just scrap off the rinds, then juice them and add. You do not want the white pith as it can add a bitterness bite that would kill a light beer like that.