This same feeling about Dubai SIXT
This year in April we book MB GLK, as Platinium member I think we will have one class upgrade to ML model. Sixt staffs told us thay don't have any ML or GL model on terminal we can take only what we book. I go to websiete and check that thay have GL model in offer much cheaper than our GLK model. I make quick call to germany office and book GL after 15min we had keys to MB GL car at Terminal 1.
On way back from Abu Dhabi I want again book car thru SIXT (thay show on website that they have office at Abu Dhabi) but answer was we need 48h to delivery our car to Abu Dhabi airport terminal .... we finish our booking with Hertz and this time we take Volvo S60 online and on Hertz desk we have upgrade as Gold member to nice new BMW730Li. On Seychelles last year Hertz upgraded us two class w/o any problem, I don't ask thay give us nice Hyundai ix35.