As Vereeken picked up, my car is Australian delivered therefore ROW with no window sticker.
The sticker under the front bonnet states the following codes (along with my interpretation):
L697 = Diamond Blue paint colour;
C23 = Australia
243 = Short shift
425 = rear wiper
454 = cruise control
490 = Hi-Fi
498 = Delete rear badge
559 = air cond
650 = sunroof
975 = velour carpet luggage
980 = Raf leather
So it mentions Hi-fi but not which model of radio.
The COA only states "Rear Wiper, Cruise Control, Air Conditioner, Sun Roof" and no mention of the model of the radio.
According to site that NY65912 linked (turbosition) the Blaupunkt Reno was only a US available stereo model. Assuming the turbosition site is correct and excluding the US only models, the Blaupunkt possibilities for 1987/1988 could be:
Boston SQM 23 (M688), Bremen SQR 46 (M328), Ludwigsburg SQM 26 (M686), Toronto SQR 46 (M330) or Berlin IQR 87 (M326).
I can't see how I can tell which one though....
oh and photos are shown in my garage page porsche boy:
Diamond911's Garage :: 1988 Porsche 911 3.2L