Al Ghazal taxi (+97124445885) are cheap for the return trip to Abu Dhabs as they need to reposition their fleet (they are AUH based). There may be a 30 min delay but they are generally pretty good. Being a weekend though, might be a bit grim. There is a bus service that runs from the main bus terminal in Dubai (taxi's know where) and they run every 30 mins and cost 25 DHS or so
and are top notch, their timings though may preclude a 2AM transit.
Try the airlines though (as mentioned) they drop off to all major UAE destinations and if you fly with a major it will be for free. EK and the majors all have shuttles running all the time and I think you can grip it up with them for an appropriate surcharge.
Rent a car never an option for me as I have normally cleaned out the drinks trolley!
