Santa Cruz itself has banned sleeping in any vehicle at night, so you would need to be outside the city limits. I presume from you saying along Hwy 1 that you know that. Anywhere outside the city you are likely to be ignored. There are hundreds of car sleepers up and down the highway, particularly around Davenport.
It's probably worth mentioning that the local residents are pretty unhappy about it, so there's no promise that you won't be hassled, but it's probable that you won't.