ASR defeat switch and diff. locker
 

I want to buy an asr defeat switch (from REnntech?).

I also want both my wheels to spin. What is the most effective (and low-cost) way to do this?

Do any mercedes (w124) have a locker which is not the electric way (asd) which I can get and put in my car?

Could I implement ASD in my car, which has just ASR?

What is smart to do?

I have a E500, 1993. I live in Norway.

Have been surfing the Internet for several hours and feel lost!