This is The Little Witches (1997-1999), alternately titled Les Petites Sorcières.
Auto-translated from the French Wikipedia page:
Shérilyne, a confirmed magician, teaches three little witches to use magic to perform good deeds. But the city of City Base is under threat from a shameless man, Walt Street, who desires wealth and power.
Fortunately, the little witches are there to thwart his plans.

It's a French-Spanish animated series consisting of 25 episodes that aired in Continental Europe, the Middle East and the Far East. It was also released on VHS in 1998, but not on DVD or Blu-ray, as far as I can tell.
According to the French Wikipedia page, Shérilyne is a 150-year-old witch, but appears 25; she looks like a goth version of Jessica Rabbit, with long black hair and a strapless black dress. She also drives a flying convertible car and has three apprentices: 7-year-old Lulu (who's incapable of lying), 12-year-old Chloé (who's very serious and helps Shérilyne) and 10-year-old Marine (who's known for her pranks). 16-year-old Zippo is an electronics whiz and the best friend of the Little Witches.
The main antagonist is Walt Street, a megalomaniacal business tycoon who wants to take over the city. He looks like a mash-up of Lex Luthor and the Joker, but is apparently a caricature of David Bowie (that's him hanging onto the back of the flying car in the image above). His base of operations is a LuthorCorp-style skyscraper and he's aided in his schemes by his scientific advisor, Professor Lem, his mother, Mamie Doll, his muscular chauffeur, Artie, and his strategist, Vickie.