NFPA 13 is very specific that non-combustible covered walkways and porte-cocheres do not have to be sprinklered.
8.15.7 goes through great pains to exempt non-combustible, limited combustible, or FRTW construction, and keeps on going about how to exempt combustible construction as well.
The part that freaks people out is: 8.15.7.5* Sprinklers shall be installed under roofs, canopies, or porte-cocheres over areas where combustibles are stored and handled.
However the annex notes are quite clear:
A.8.15.7.2 Vehicles that are temporarily parked are not considered storage. Areas located at drive-in bank windows or porte-cocheres at hotels and motels normally do not require sprinklers where there is no occupancy above, where the area is entirely constructed of noncombustible or limited-combustible materials or fire retardant treated lumber, and where the area is not the only means of egress. However, areas under exterior ceilings where the building is sprinklered should be protected due to the occupancy above.
A.8.15.7.5 Short-term transient storage, such as that for delivered packages, and the presence of planters, newspaper machines, and so forth, should not be considered storage or handling of combustibles.
8.15.7.5 is meant for loading docks.
Having said all that, this is one area I always check with the AHJ on, since many use the "because I said so" clause for this. You then need to decide if it is a battle worth fighting. Note that one area I don't argue about is Hospital ambulance entries, since they may see more than the typical temporary parking, and they may be kept running a long time.