I just tote lunch each day - if I don't carry the backpack, it fits fine in the trunk. In the summer, I can get my clothes AND food into the trunk, but in the winter I use a backpack cuz I need more clothes. Also, my week can be unpredictable - some days I must drive to be able to make offsite visits (like tomorrow) that I learn about on short notice. So I pretty much operate one day at a time, hoping for a four or five bike commute week.