radio freqency (RF) remote control, whereas in Germany or Europe and Japan they early E34 were with IR and later with radio frequency.
Basically no problem. You have to buy that plug and mae the wires according to the wiring diagrams. On Johan's website there are the details. But it could also be that the wires are there too because they are needed also for RF system.
But that you better have to check out or someone for you.
With a little basic knowledge and the instructions from Johan's website and maybe others here on the board can help, in case you have questions about that.
On the other hand, if you want to sell the IR system again, just post it on the E32 forum next door, people are always looking for that.

E32 750iL 11/88, E32 750iL Highline 03/90
7 series Tech Tips

• IR LED Program connector (pic) - hurleyandstrings 2008-07-29 18:05:00 (179 views)
  • the circular 'bulb' is the light sensor (url) - shogun 2008-07-30 00:22:22 (102 views)
    • Re: the circular 'bulb' is the light sensor - hurleyandstrings 2008-07-30 17:15:12 (75 views)
      • I found a pic (url) - shogun 2008-07-30 21:03:57 (121 views)
        • Re: I found a pic (pic) - hurleyandstrings 2008-07-30 21:28:33 (139 views)
          • these are for different stuff - shogun 2008-07-31 00:05:09 (78 views)
            • Re: these are for different stuff - hurleyandstrings 2008-07-31 00:55:10 (79 views)
              • Re: these are for different stuff (pic) - hurleyandstrings 2008-07-31 00:58:53 (114 views)
                • best is someone checks on his E34 - shogun 2008-07-31 05:52:33 (91 views)
                  • Was this a US option? - kfister 2008-07-31 09:55:41 (70 views)
                    • no, the socalled switchblade IR remote was sold everywhere (nt) - shogun 2008-07-31 19:22:02 (86 views)
                      • Thats funny it's not in the ETM's - kfister 2008-07-31 20:05:27 (82 views)
                        • Re: Thats funny it's not in the ETM's (pic) - hurleyandstrings 2008-07-31 23:58:01 (112 views)
                          • Look at the '91 E32 ETM! - kfister 2008-08-01 00:58:12 (76 views)
                            • Re: Look at the '91 E32 ETM! - hurleyandstrings 2008-08-01 14:18:23 (70 views)
                        • maybe on E32 only, you could be right - shogun 2008-07-31 22:07:39 (66 views)
                    • Re: Was this a US option? - hurleyandstrings 2008-07-31 16:01:45 (76 views)
                      • DOES ANYONE WITH AN E34 '91 have - hurleyandstrings 2008-08-02 21:18:04 (90 views)
                        • Re: DOES ANYONE WITH AN E34 '91 have - rick540 2008-08-09 05:10:54 (77 views)
                          • got answer from BMW Germany for part number - shogun 2008-08-19 10:13:49 (73 views)
                            • Re: got answer from BMW Germany for part number - hurleyandstrings 2008-08-20 02:54:08 (64 views)
                              • it looks lie the U.S. version E34 always came with RF - shogun 2008-08-22 08:02:52 (70 views)