Where was the fun in driving if you couldn't occasionally flirt with the prettier mechanics? Haruka'd always thought it was a shame that so few women got involved on that side of things... Michiru was probably thankful for it, but that was besides the point entirely.
Getting out from underneath the car to someone actually there gave her a reason to pause. This wasn't going to blow any kind of cover, right? Just because she was a racer didn't mean she was dumb. "Did they send you here to make sure I haven't blown up my car again?"
Seriously, you did that once and nobody ever let you forget.