| | Re: advice on what my wifes really saying
I know that you are hurting and want your wife back. The rose on the car thing kinda makes you look needy or desperate, in my opinion. I have no idea as to whether it will work. Here's the thing, I don't know how you treated her before the separation but if you treated her well and expressed how you felt about her, then she already knows that. Leaving a rose and stuff would be appropriate if you two were on those terms. Currently, you are not. I think that the advice about counseling is good if she is willing to go.
It seems that her "need for space" is because she is unsure about your marriage. People generally don't go putting a perfectly good marriage on pause just because they feel like it. You need to be really honest with yourself and see if there is any reason why she would want/need to get some space and make up her mind about the marriage.
I am not big on ultimatums. You need to think about how long YOU want to be in limbo. Set a mental deadline with yourself. Do what you feel is appropriate to save your marriage and then, if she does not come around, get on with your life. If you are a decent dude (and you probably are), you can find someone who will be more sure about a relationship with you. Good luck.