Commercial auto comes in three main forms. A garage form suits auto businesses such as dealers, where the public may drive the vehicles and the business handles other people's cars. A motor carrier form is written for businesses that transport property by auto. The business auto policy (BAP) fits an ordinary business that uses vehicles in its work, such as a florist with delivery vans.

Who needs garage coverage: public repair shops, dealerships, attended parking lots, and any situation where the public might drive the business's vehicles or the business has care, custody or control of other people's vehicles. California Insurance Code §11580.9(a) sets which policy is primary in these settings: - When a vehicle is operated by a person in the business of repairing, servicing or road-testing vehicles, or that person's employee or agent, the policy issued to the business is primary and the other policy is excess (§11580.9(a)(1)). A mechanic road-testing a customer's car is covered first by the shop's garage policy. - When someone outside the business is driving, such as a customer on a test drive, the business's policy is excess over all other insurance available to the driver (§11580.9(a)(2)). An excess policy may limit itself to the financial responsibility limits of Vehicle Code §16056 (§11580.9(e)). The usual rule that the owned-auto policy is primary, in §11580.9(d), yields to subdivision (a).

Garage operations is a broad term. It reaches the use of locations for the garage business, the business's autos, and the operations necessary or incidental to that business. It does not extend to the owner's personal driving.

The CDI outline says garage liability provides four major coverages. Study sources commonly group them as premises and operations, products and completed operations, automobile, and contractual liability. Damage to a dealer's own inventory is first-party physical damage, not liability, so it is handled separately.

Why one garage form instead of a CGL plus a commercial auto policy: a garage business has auto and non-auto exposures that run together. The CGL excludes most auto risk, while a business auto policy covers only auto risk. One form built for garage operations reduces the chance of a gap or a dispute between two insurers. Customers' cars in the shop's care are not covered by garage liability; garagekeepers coverage is added for that exposure.