Renting a car in Germany -- any advice?

[cscmc1]

Hey folks -- I'm finally getting around to taking my honeymoon in November. We'll spend 12 days in Germany, and I would like to rent a car. We're flying into Munich, so airport pickup there would be ideal. I have been watching kayak.com for rates, but wondered whether anyone had any other tips for renting in Europe. For example, is there any way to rent a small diesel car, specifically? And any advice on renter's insurance? My CC claims anything under 15 days in all but a handful of exempt countries is covered, so I don't see any reason to spend the extra $. Thoughts?

Thanks!