California has a definate car culture and one of the reasons for that is the distance from one part of a city to another. For example, if your hotel is in Carlsbad Village--the downtown area and you want to take the kids to LEGOLAND, you will need a car to get there. Well, maybe you'll be provided some sort of shuttle, but the point is, having access to a car is very convenient.
A pick-up truck is especially useful for carrying your ATVs, (All Terrain Vehicles,) dirt bikes and other "toys" for beach or desert activities
You can find a lot of free of charge parking lots located just on the main street of Carlsbad that is Carlsbad Avenue. They are located mainly close to numerous businesses and as you can see on my picture they are just much bigger than I used to see in Europe, at least in most European old towns = NO GYMNASTICS needed when you take out of your car :-).
But at some places it's a little bit more difficult to find a free parking lot and they maybe paid. Usually around some more busy businesses in the downtown.
But, never mind, it isn't difficult to park a car there - at least when I was there: on sunny early Saturday's afternoon in April.
Watch for traffic signs.
Look at my picture, please. In some intersections they don't allow to cross the one street by pedastrians = you must walk and cross 3 streets to get to to the other side of your street.
It seems that they often support rather drivers than pedastrians = majority :-).