I kinda do many things today.. whew..!
I purchased the rent-a-car which I will be using while I'm in California.
I bought it on Travel Jigsaw. which is Korean site, and it's the same website with Carhire3000 in UK.
I'll be using it for 17 day, 11 - 27 May. I didn't know about the renting-a-car price, but it is pretty big! I paid 616 dollar. And it was the cheapest one.
Road trip in California... It's totally worth to be paid the money!!
------------------------------- Updated ----------------------------------
I canceled the purchase. Because I will be able to use a car of my relatives! :)