I don't think your spouse's problem is with the Lexus in specific, it sounds like she's just not really a car person. I love cars too, for instance when I have a lull in the middle of the day and I drive by a car dealer, I'll stop off and see what they've got on the lot. If I can convince a salesman I'm not worth their time and they'll let me take something for a spin on my own I'll do that too.
When we were first living together this would cause big problems lol. She HATED looking at cars, going to car shows, hearing about cars. I kept trying to include her in my hobby. What I finally learned was its just not her thing. Theres plenty of other stuff we share interest in and enjoy doing together, but I enjoyed my hobby more if I just enjoyed it myself.
When it came time for her to buy her car...she bought what she wanted and I had no say in the matter at all (her Prius). In fact...she wouldn't even let me drive it when we first got it. That changed when she was faced with the idea of having to service...fuel it...maintain it...wash it...and insure it without any help from me ;)
So the answer is, there may not be much you can do about it...