Ok upon further diiging looks like the pv panel would be a little large for the hood of the jeep.
This is entirely reasonable.
The power required by an automotive application dwarfs the power consumed by a home - even an ordinary one, let alone an energy-efficient home trying to get along off-grid.
A horsepower is about 3/4 KW. A car cruising on a level freeway at speed is using maybe 18-20 HP, and an off-road vehicle in less paved and/or more rugged terrain or a car on a shopping trip doing stop-and-go will be using significantly more.
So assuming three hours of use per day you need at least 100 HP HR, for the car, or 75 KW HR OUT of the car's batteries per day. Assuming 5 solar hours for the insolation and a desert location with no cloud cover (where an ordiary house's needs would be covered by 5 KW of panels and an eco-freak's efficient house could run on a lot less), the car needs an additional 25 KW of panels times a storage inefficiency multiplier for TWO trips to storage: The car will probably be in use during the day so you first have to store the power in the house batteries, then charge the car while the sun is mostly gone. That's JUST for the car and nominal use, like commute or shopping in a nearby town. If Barbie is doing a lot of cruising with her friends she'll need a bunch more, or she'll be prone to running out of juice while out on the town in the evening. And for a rural setting - likely if you're doing a home-power system and a jeep - the local town is a long way away and probably over some serious hills. (Hills are BAD - now you need over a hundred horse for long periods as you climb them rather than the 20ish for level cruising. What would run you for an hour on the level is gone in 10 minutes of hill-climbing. City or rush-hour commute stop-and-go traffic is similar.)
So having an ENORMOUS solar instalation at the playhouse to power the car, because the car needs a LOT more than the house (like a factor of between 6 {mundane house, tiny car usage} and 60 {eco-house, moderate car usage}), is the right lesson to be teaching.