That interlock foiled my wife....I got this frantic upset call from her a couple weeks after we got the 300E.... "My key won't come out, it won't give it back!" So I calmly asked, "is it in park?" Her: "No" (Click).

She'll never live it down.
Now she always remembers to put it in park. The thing that gets me in that car is having to press the brake to move the shifter out of park, thats just annoying....I never do it in my SD....I can start it, and put it in reverse/drive, without ever having to touch the brake.
If I bought a car (that I was going to drive regularly) with the interlock I'd probably remove it. Its extra obnoxious when you want to do work on stuff like the brakes, and need it in neutral so you can turn the rear wheels, you have to put the key in to get it to neutral, and leave it because it won't give the key back unless its in park....so it sits there buzzing the whole time. Very annoying.
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-diesel is not just a fuel, its a way of life-

'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)