a) The policy is primary for the named insured’s covered autos that another motor carrier hires or borrows if a written agreement between them requires that the named insured as lessor hold the motor carrier as lessee harmless. However, it is excess over any other collectible insurance if the written agreement does not have this requirement.
b) With respect to trailers, coverage is provided on the same primary or excess basis as the liability coverage provided for the power unit if it is a covered auto. However, it is excess if the power unit is not a covered auto.
c) Coverage is primary for any Trailer Interchange Coverage provided in the policy.
d) Except already noted, this policy provides primary insurance for any covered auto the named insured owns and excess insurance for any auto not owned by the named insured.
e) Under hired auto physical damage coverage, a covered auto the named insured leases, hires, rents, or borrows is considered an owned covered auto. The only exception is when such auto comes with a driver.
f) Coverage is always primary when liability is assumed in an insured contract, regardless to the above provisions.
g) The insurance company pays only its share when any other insurance covers the loss on the same basis, regardless of whether that coverage is on a primary or excess basis. Its share is the proportion that this limit of insurance bears to the total of all limits of all coverage forms and polices that apply on the same basis.