Yaris ISO stereo adapter not fitting

[Theo1999]

Hi all,

Recently I purchased a new aftermarket stereo for my 2005 Yaris 1.0 T3 (https://www.amazon.co.uk/Sony-DSX-A202UI-Head-Unit-Mega/dp/B01AUXO0WK) It had good reviews and was within my price range, and just assumed that it would fit in my car, which it didn't and only does now due to modifications , however that is not the problem. The problem is with the wiring. I soon noticed  as I was fitting the new sony stereo that some of the cables were not going to fit, so I purchased an iso adapter(http://www.ebay.co.uk/itm/251334381714) which I presumed would put all the rest of my problems to rest. As you can see from the item title is is build for post 1999 Yaris' and all the other adapters I have come across look identical, so when I went to plug it into my car this morning and it does not fit I was dumbfounded. What really baffled me though is that one out of the two plugs fits absolutely perfectly and was hoping someone of this forum would have a bit more knowledge that me on the situation. As you can see from this photo(sorry its not crystal clear how many wires there are) but there is a black wire on the iso connector by the red one. It seems to me like the only one that doesn't have a slot to go into on the sony connecter is the orange wire which from looking at the writing on it is an "illumination" connecter. I can only come to the conclusion that the orange cable is the reason it is not fitting but for the life of me cant understand as surely and iso adapter would enable me to then put any modern stereo in my car? and seeing that the iso adapter fits to one of the two plugs, I'm inclined to believe I have the right adapter. In the second picture below you can see that the sony adapter has one less prong to go into than the Toyota iso adapter has. I hope someone can shed some light onto what is going on otherwise my new £40 stereo is going to have gone it waste and  past the return date. Thanks in advance.