Peacocking with fancy cars is old school. It could work but you have to put your brains and pockets to work. Peacocking the car is like the oldest page in the book, you gotta think outside the box.
It might be old school, but it works. He has the car and its shown its usefullness. Everyones avoiding the question now.
You have the car and you've got their interest. GOOD.
Now it's up to use your game to draw them in. Keep or roll your window next time and when you catch someone looking say "Didn't your mother ever teach you not to stare?" *jokingly* they'll validate themselves afterwards and if they actually are interested they'll come up to the window to explain.
Now keep the car running (FTC) and start building the attraction. If yo're any good you can say "Here, I'm just gonna park over there".
Park, continue convo while sitting in car (FTC). Eventually if you've built up enough attraction you can plan to talk to the set later. I can't think how to isolate in this situation so the next time you meet either find your target alone or arrange to "hangout together" or #close when the obstacle excuses herself for a moment.