An update on pricing in Germany:
Sixt has about the same pricelevel like National and Avis.
I booked Sixti for half the price...and will get A Volvo S-40 or a Ford Mondeo.
Sixti change their rules:
The most important changes in the rental conditions:
• No charges for cleaning, refuelling and reservation changes
• Increase in the free kilometres to 500 kilometres for vehicle categories above the SMART
• Increase in the maximum rental period to 100 days
http://www.sixti.com