We were two families, in two vehicles, one a land cruiser and the other a ford explorer, left Dubai at 12.30 in the afternoon, heading towards Buraimi to cross the border into Oman and onwards journey to salalah.
First experience was that on reaching Al Ain there are no clear directions to get to the Buraimi crossing. However, we found the way and ended up at the check post, this was the Oman one and got the paperwork done to obtain visa's for all. At this point it did not strike us that we did not have an exit stamp from the UAE.
That was not an issue, there was hardly any crowd at the border and the facilities at the check post were excellent.
If you do not have Oman insurance like us you can buy that there, it cost us dhs. 240 for the same. All takes very little time and you are on the way.
We chose the Buraimi route to avoid Muscat and thereby reducing our distance by 100Kms but since the roads do not have any lights etc while driving in the night we went upto Nizwa before branching off to Salalah.
check out the following link for the map of Oman.
We drove on till Nizwa where we took a break as it is advisable to top up on gas at every station from Nizwa till you reach Salalah as you are driving through a two way road in the middle of the desert, there is not even a little shaded area if you wanted to rest.