It’s certainly possible. I had £449 taken off mine thanks to Dave in the Q4 offers thread. Like last time I was due to change I called my local VW dealer and of course, the salesman was full of ‘oh no, sir. We don’t make any money on Motability and can’t discount even if others are’.
I don’t know why I try with them still 😀
Best bet with Tiguan deals is Marshalls VW Oxford, they have traditionally offered £500/£250 off and will probably do so again if you mention Vertu are offering that deal. Hull is another area that springs to mind for Tiguan deals.