The warehouse level is quite like the Ancient City level's goal. The level is designed as the warehouse where the Ark of the Covenant is stored in a crate. There are many vehicles including: a jeep, a convoy truck, Colonel Vogel's Hatay Mark VIII Tank, two bicycles, and two motorcycles.
The easiest way to get the required studs is by shooting a target. Select Enemy Officer, for example, then go all the way to the right and shoot the target using your Hand grenade as many times as necessary until you get 1,000,000. Another option is to jump in the tank and continuously shoot at the target in order to get all studs.
You can also create your own personal racetrack and race one of the vehicles around it. You can ride a bicycle and a motorcycle by aiming a bazooka or grenade at crates that hang on the ceiling, but it's a very slow way to gain studs compared to the previous methods. There are also hanging ropes that allow you to zoom in and out by jumping on and jumping off.