Where is the best city in cali for buying used cars?

[hi5u]

hi there

im planing to move to cali for about a year to start a business in buying used cars and transport them to the middle east

but i dont know what city is best for that

ill be buying mostly new models of cars like vets c6 and zo6 ,mustangs, jeeps, esclades

so where is the best city i should go to?!!