Prior to your heading out on the road on your vacation, get your car a physical.
Cooling system (radiator coolant)
Lube, oil and oil filter
Emission control (if due)
Fuel (filters, etc.)
Tire condition (do you have a spare tire?)
Tune-up (if due)
Also, have the service technician evaluate the engines performance, Heater and Air Conditioning and defroster, windshield wipers in good working order, and is your electrical system (horn/lights and directional) in good working order? Do you have your safety tote in the trunk for emergencies?