Idiomatic expression, implying that something is under control or taken care of. Superlative of the phrase "I'm on it."
Sam: "I need this done by noon!"
Dave: "I'm all over it!"
Politically correct synonym for "ghetto cruiser" and/or "pimpmobile". Other synonyms: barge, boat, land yacht, tank, tuna boat. Usually in reference to large late model (1989 and earlier) domestic luxury cars, sometimes in poor condition.
That hoopty is falling apart; it needs a lot of work.