Cheers - jjst took the plug off the dedicated point - looks like toyota may have had this in mind for either map sensor ecu or BOV - just never got around to it ..
Another little mystery ive found on the gt4 with no logical explaination to be seen ( like why have clips under arches and along doors that just happen to be perfect for rear mounting the battery cables )
Seems like alot of these things for the rallycars may have filtered thru to the road goers