Actually mine has two slots in the glovebox door, but I wouldn't call those actual holders, as they are only about a quarter of an inch deep.
But just drink out of 20 oz coke bottles or watewr bottles... easier to dealw ith if you ask me. and I don't drink coffee in the car, I prefer to sit and drink coffee and take in the environment.
'92 300CE - Sold
2004 C240 - C7 Wheels
2015 ML350 - P1, Pano, Ash poplar wood, Sport Dinamica interior, Running Boards Keyless go.