If you want to go see America, get away from the "population centers" and drive across the back roads from National Park to national Park and really meet the people who live there. The majority of the big cities right now are depressed and the people living in them are feeling negative...but people stuffed into big cities always feel that way for the most part...not all of them though.
Your in New Zealand so that would mean you would probably fly into "Lost Angels". There are things to do there. The Hollywood thing, Venice Beach, the prominade in Santa Monica, The movie studio tours, Disneyland...(but do not go into Disneyland and sneak off into a quiet spot and have sex with your significant other...they have cameras everywhere!) La Brea tar pits and some other things. If it were springtime you would smell the blossoms from the trees along the streets near the hillsides...on the other side do not use your cell phone as you drive up the 405 from LA into Burbank-the lowlifes sit in the hills stealing phone number from active cell phones and you wonder why your bill is so high!
You can drive up the coast all the way to San Francisco or you can take the train just up to Santa Barbara for the day.
There is from the border of Mexico all the way up to San Francisco the California Missions which come from the days of the Spanish empire. A priest by the name Juan something or other walked north and the story is that at the end of every day where he stopped he built a mission so there is a string of missions all along the coast. I don't know about the part where every day he stopped he built a church because if so this dude could walk a lot in one day!
if you drive up the coast their is the "Hearst Castle", the old summer residence on a newspaper giant which is too much to see in one day. There is camping along the coast in Big Sur, the aquarium in Monterey and finally San Francisco.
Or you could head east out of L.A. and go to "Lost Wages" and have some fun loosing money, but they have great deals on hotels. Take a flight over the Grand Canyon from there. Get married again or for the first time in one of the fast chapels they have in Las Vegas.
Drive up into Utah and take a right turn to go see Zion National Park to cool off in the river there. Head east out the back of the park to Bryce National Park. Then on to Capital Reef National Park and then east up to Arches National Park.
You can go east up the western slope of the rockies to Grand Junction in Colorado and maybe pickup up the radio stations from Los Angele's as you gain altitude. Back in the 70's the radio stations in Los Angeles were fighting for "who's got the best radio station". One of them went down into Mexico and put up a radio tower and broadcast with a "million watts" of power to beat out the others. (It was illegal to use that much power in the states.)
Or you might want to head south to the lower part of Colorado to what is called "Four Corners" where the geographical corners of the states of Arizona, New Mexico, Utah and Colorado meet. Then you can brag to the relatives back home you went to all those states. From there you can go see where the Cliff Dwelling Indians used to live. At various points along the roads the native Indians will be selling silver jewelry they make for crazy high prices...but their craftsmenship with silver is excellent! You can go east through southern Colorado to Durango and ride the old steam train up into the mining towns. If your still going east you would want to stop off at Sand Dunes National Park where I think there is one of only two rivers in the world that actually have waves like you do at the oceans.
From there you can go north to Boulder and check to see what concerts are going on at "Red Rocks" a natural amphitheater among the hills.
You could go north through Denver, stop off to have some Rocky Mountain Oysters...
At this point you can continue east or go north into Wyoming and head back west to Cody, Wyoming where you should really STOP AND BUY A FEW CANS OF "Bear Spray" for the grizzly Bears in Yellowstone National Park.
To get there you want to go to the east entrance of the park so that the roads you follow will take across the path of "Chief Joseph" as he his led his tribe, the Nez Perce, away from the pursuit of the American Cavalry trying to reach Canada. (He made fools of the army while doing this!)
As you climb higher into the mountains your moving into the territory of the Grizzly Bear and you had better believe they bite...
When you get to Yellwstone through the East Entrance you'll being going into Lamar Valley, the area where most of the wolves live. Have a video camera ready...you might see them hunting the Caribou. You will probably have to make reservations to camp in the park, Check into this before you leave New Zealand!
Leaving Yellowstone you could go south through Idaho to Salt Lake City in Utah to participate in the "Morman 500"...rush hour traffic everyday! Then across the salt flats to Reno, Nevada and Lake Tahoe. On your way back to San Francisco you could stop off at Yosemite National Park which is really nice too and swim in the Merced River to cool off.
In San Francisco get the Chinese food!
How long would this trip take? Beats me...my last trip from Seattle to New York took me almost 3 months and you can drive it in less then a week!