Recently took my 96 SL 320 to the dealer because the battery went dead, and after jump and charge the top and roll bar switches are constantly lit and do not operate the mechanisms. For $115 ( well, they did wash my car too) the dealer told me the control unit had failed and repair would cost $3500, $2900 alone for just the part #1298205026. Of course I did not bite and quickly found many parts options ( I am convinced the dealer diagnosis is correct.) Thanks to Forum I found the simple way to access the unit behind the passenger seat, and was surprised to see that the part in my car had a different #. A call to the parts dept. revealed that the part has several superceded numbers. I found an NOS unit in a box in Colton Ca. with one of the #'s provided by parts (ending 3926) for $650.00 and it is on the way. Now, my question is: It looks like I can easily access this part and it is two harness plugs and secured to the floor at the corners. Is it a plug and play, or does it need special programing by a tech? If its plug and play, I'd hate to pay the dealer $600 for what looks like a simple half hour job.