Originally posted by rjnonnie
I am supprized that your 99 E300 does not have child proof door locks. My 98 E320 has child proof door locks on the back doors. They are activated by the switch located between the left side window switches on the center console. Double check your owners manual to verify if you have child proof door locks.
On my C230, that switch is to lock out the rear window switches. Are you sure it disables the inside door handles?