I need a suggestion for my sitch.

Should I tell my W I got a car, let the kids tell her or let her see it Friday night when I got to my sons concert?

Me:56, W:51
D:26,S:24,S:22
Married:18
Bomb 9/27/06
Separated 11/27/06
Divorced 10/6/08
Leaving it up to God