I used a Radio Shack P/N 276-1101 (1N4001) basic small diode, rated at 1A continous, but I doubt it sees anything close to that. package of two incl. tax less than a buck.
EDIT - Here is a better description of the soft stop disable mod:
1 Remove the one screw in the sunroof control cover, then pull the whole cover off (If you try to pry up just the clear plastic lens you'll mess it up)
- srcmod1.jpg (15.53 KiB) Viewed 7099 times
2. Remove the screw that holds the sunroof controls to the headliner and pull the controls out, disconnect the one connector and take it to a better place to work on it.
3. On the back of the sunroof controls, there is a black rectangular box that holds the control circuit board.
- srcmod2.jpg (12.49 KiB) Viewed 7099 times
It may be possible to remove the two ("C") screws and then unhook the four ("B") tabs to take the back off the black box without removing the black box from the rest of the assembly, but I unhooked the four ("A") tabs to pull the black box out of the assembly, then took out the two ("C") screws and unhooked the four ("B") tabs to open the thing up.
NOTE Inside the black box there are four tiny white plastic pieces that may (will) come out of place if you take the circuit board out of the case, and these are important, so don't lose them.
- srcmod4.jpg (20.22 KiB) Viewed 7099 times
4. Solder a diode between two terminals on the circuit board. Pay attention to the polarity, a diode is directional, the silver line on one end has to be connected to the correct terminal. Solder it in in such a way to allow the black box cover to fit back on ok.
- srcmod3.jpg (15.58 KiB) Viewed 7099 times
5. Test it out before you put it all back together
6. put it all back together (and don't forget those little white internal pieces I warned you about)