The detail to resolve first
Describe the packed instrument case and whether it can be placed with other luggage. If it needs its own secure space, say so before a vehicle is proposed. Do not send instrument valuations in a general enquiry unless a specific arrangement requires them.
Prepare a workable enquiry
Count the bags separately from the passengers. Include bulky items and provide dimensions where useful. Ask for the exact configuration rather than relying on a vehicle-category label.
Check the written arrangement
Ask which parts of the itinerary are included, how waiting is handled and what to do if the schedule changes. Identify any tickets, guiding, specialist assistance or extra stops that require separate arrangements.
Keep the written confirmation available to the passenger. An enquiry or a WhatsApp conversation is not a confirmed reservation until the specific journey has been accepted.