What would cause a Mercedes S500 not be able to be put in drive?

Several issues could prevent a Mercedes S500 from being put into drive, including a malfunctioning transmission, low Transmission Fluid levels, or a faulty shift linkage. Additionally, problems with the brake system, such as a faulty brake switch, can prevent the gear shifter from moving out of park. Electronic issues or dashboard warning lights may also indicate a more complex problem requiring diagnostic tools. If these basic checks don't resolve the issue, consulting a professional mechanic is advisable.