Trans. Failsafe, engine. Failsafe OUT THE BLUE

[X5kindathing]

Yesterday I parked the car (2006 x5 4.8is Dinan stage II with 50k on the odo) in the driveway, detailed it and when I went to start it .... Nothing! All the clusters are working all lights are on just nothing! Turn the key and nothing.

It has given NO previous warning from an engine or transmission stand point.

It needs to be noted that just the day before and for e firt time the suspension self leveling warning came on but went away. I have brand new front airbags.

I just replaced my battery as the old one tested as "dead" yellow light and confirm by the autozone people as only putting out barely 11 volts.

Does the code need to be cleared before the car can start again ?

Any ideas what to try next ?

Thanks