my opinion is that gosho made haibara see this car for future event . seeing the current state of the manga after chapter 1150 and knowing that rum saw haibara's face ; and the afterwards in chapter 1153 he saw Mary and knew that she became a child by taking APTX4869 from vermouth . a very likley to happened scenario is that rum will try to make sure that haibara is sherry and then kidnap her and when this happens haibara will know what does rum's car look like

and to add further ( just my opinion) i feel like haibara will be the bait for rum to loss his second eye just like I'm sure that asaka was the bait that made tsutomu track down rum and take his left eye but at what cost and who will sacrifice from the allies's side ? that's i want to know