Yup that’s exactly how you do it. I had similar not over 7 seats but the difference between a 60 enyaq and the 85 like seats, adaptive cruise etc. If you can genuinely justify it they generally seem to listen most of the time. Especially if they give you a list of cars and you can show why none are any good and why then show them what will work and why. Sometimes being neuro divergent is a asset, lol.
Definitely though I tend to run on the edge of that double edged sword lol being able to pick out in depth flaws in the cars that most miss really helps😆
Also building a rapport and being brutally honest help lol 😆
I did make my adviser stop mid sentence as she was trying to tell me cannot choose fuel line on the kodiaq its the same car and basic price, she literally loled then apologised for her mistake. Even tho in the end it was a 5 seater and not technically within my grant.