Ray J -- I'm Making it Right with My Ex ... With a Mercedes

Ray J just dropped $165k for a car, on the woman who got arrested for beating him up.

Ray gave Princess Love -- who allegedly attacked Ray J in February in New Orleans -- a 2015 Mercedes S63 AMG for her birthday.

She needs a car, because after they broke up he ungifted her 2012 Bentley.

We're told the two are talking again, but Ray says they're not dating.

And get this ... Ray sold his Ferrari and plunked down the proceeds at RD Whittington's Scottsdale Sports Car Group to buy 2 cars -- the Mercedes for her and a Maybach for him.