First of all have lot of fun, as its brilliant drive and I'm waiting since few years to repeat again without any luck.
Road and car safety tips for long road trip to Salalah:
Check all fluids level constantly for few days prior to your trip, both before driving and after.
Get all bushes, belts and hoses check from proper mechanic with expected remaining life.
Carry the good size tool box, gloves, duct tape, mseal, cable ties, tie-down straps for safety.
Inflate all tires at 35 when fully warmed up, means start with 32 and check after an hour to top up.
Stop every 150-200 kms at every fuel station for 15 mins to check and rest yourself and car.
Refuel at every gas station spaced roughly 200 kms away to avoid no-show in next station.
Avoid high speed for long hours, keep it at 120-140 is good for engine and fuel efficiency.
Take 8-10 hours sleep in advance for 3 consecutive day prior if you are planning to drive in one shot.
Don't eat full stomach meal, you will fall sleep, no matter how much you were rested before.
If you feel sleepy, pull over far away in barren land (either side) and take a nap, than pushing.
Start at night so that you can reach Salalah before it get dark, as driving in night is bit risky as incoming traffic blinds you very much on one-way road. Starting from Dubai at night till Muscat is good well lit road, so you will hit that one-way road during daytime.