Floyd Mayweather -- I Finally Got My $4.8 Million Hyper Car!

Behold ... one of the most rare and expensive cars in the world -- a $4.8 MILLION Koenigsegg -- and it's now officially in Floyd Mayweather's garage.

TMZ Sports broke the story that Floyd was gunning to buy the ultra-exotic lightning fast whip back in June -- and now, the deal is closed.

The car is a Koenigsegg CCXR Trevita -- one of only two of its kind in the entire world -- and goes from 0-60 in 2.9 seconds. It tops out at 250 miles per hour!

But don't call it a "super car" -- Floyd says it's technically a "Hyper car."

Yeah ... you drop $5 mil on a car, you can call it whatever you want.