The best way to answer that is, probably. You agreed in the past to buy the car and I believe you said the money coming in was supposed to go towards that. Or really the $7k was. Would buying a car bring your closer to your goal of fixing your marriage or would not buying a car bring you closer? I am not advocating the idea you can buy her love. It is just that if you made a commitment, it is best that you stick to it.
Remember, a good chunk of her frustration and cause for kicking you to the couch was wasting the $7k on something (in her eyes) as frivolous and wasteful as a casino. You have a chance to partially redeem yourself on that one.
Me: 42 W: 32 Married 7 years together 8.5 S1: 7 S2:7 Bomb #1: 09-16-13 Recon #1: 11/13 A discovered 04-03-2014 W filed D 05-19-14 but never served me I filed D 12-02-2014 S 05-31-14 Divorced 5-19-16