Called the police and they said to report it, both parties need to be present. They also said that if damage is over $2000 then a report has to be filed, so they suggested I try contacting the lady.I'd do the file a collision report thing so at least it's on record in case she has a sudden case of whiplash or tries to report you as leaving the scene without giving her your info.
Still don't understand why she didn't take my info, not even my name. I shall contact her and ask.
I wonder how much a new bumper is for a Lexus?