It's probably to do with the lighting of the 3D model. Here's a better view:
I know that but couldn't the mangaka at least choose a better car that has more class and is more tasteful than that ostentatious and vulgar thing?
For example, the Rolls Royce Phantom Drophead Coupé Waterspeed Collection or the Aston Martin Vanquish. Tons more class than a Maybach.
Maybe personal preference/taste? Also the fact that it's the supposedly most expensive supercar in existence, which emphasises the cost of Claude's present?
I agree with you there. Heck, I even prefer the Bentley Mulsanne to the Maybach, but everyone has their own personal tastes I guess. Obviously some people like Maybachs because they lasted until last year, but not enough to keep the brand around. Maybe that's why Komi sensei chose to use the Maybach, as an homage to the brand's memory.
I like the Mercedes Benz C63 Black Series Coupé even though it's not as super as Bentleys or Rolls Royces.