My trusty Honda Civic is a cheap rental that will get you there efficiently. This old car averages 34 mpg. It's definitely not a stylish ride, and it spends a lot of time on my dirt driveway, so it'll be a bit dusty inside and out. But it'll get you where you need to go. It's also pretty fun to drive.
No A/C. You'll want the windows down anyway, driving around the Central Coast.
I also have a trunk-mounted bike rack for 2 bikes if you're interested.