Hey Vman,
I own a real estate appraisal firm and appraise in 22 counties throughout NW Ohio, so I too drive a lot. Sometimes I cover over 300 miles in one day appraising 5-6 houses. I find the Z1 to be highly adequate.
Don't let startup time dictate your decision. Haven't you heard that good things come to those who wait? Plan your day ahead and leave the car running in the driveway between appointments. Your rich, you can afford the gas right? The Z1 has sooooo many more features than the D2 and D3 and I guarantee that you'll utilize many of them, including Bluetooth, Sat Radio and