I just did a quick search on google but here are the results.
1 Las Vegas/Paradise, NV 22,415 1,310.40
2 Stockton, CA 7,046 1,060.96
3 Visalia-Porterville, CA 4,238 1,031.46
4 Phoenix/Mesa/Scottsdale, AZ 39,535 1,022.88
5 Modesto, CA 5,081 1,005.13
6 Seattle/Tacoma/Bellevue, WA 31,231 974.96
7 Sacramento/Arden/Arcade/Roseville, CA 19,558 957.65
8 Fresno, CA 8,363 952.96
9 Yakima, WA 2,155 930.54
10 Tucson, AZ 8,508 920.00
The second number is Ranked by the rate of vehicle thefts reported per 100,000 people based on the 2005 U.S. Census Population Estimates.
This list was 2006, I saw on the news the other day that Sacramento was up higher on the list this year.
Sucks bro.