We are thinking for starting in San Diego and making our way up past Newport Beach, Santa Barbara,Pismo Beach, Monterey, Bodega Bay & the onto San Francisco for a couple of nights. We dont want to go back the same way we came. Any suggestions as to the most scenic way to go back to San Diego. We would also like to go thorugh Yosemite & maybe Mammoth. We would like to try and avoid the busiest road if possible. We are going to go in September. What is the weather like that time of year?