Diff. lock-Because I've never seen it, it doesn't exist

Toyota started the option with the Tacoma in '95 and it's still an option. 4Runners had the option from 96-02, and I hear it's back but haven't checked.

Jeep has has the option on the Rubicon which started on 03.

Mercedes has had the option for a long time on the G wagon.

Audi had the option on some of their cars in the 90s.

Dodge put the option in with the power wagon reintroduction in 2005.

I am sure there are other, that's all I can think if right now.