Thanks for your time and words of caution. I wanted to post back and let you know that your words of wisdom did not fall onto deaf ears. The planned meeting (for today) with the GTI owner fell apart, and is now planned for Monday evening. I previously met the GTI owner (2 days ago) and did a brief test drive. The car is 100% stock.
The "sales lead" for this GTI was initiated by my ex-wife. I plan to meet with her tonight and again on Sunday. During these meetings with her, I will echo your comments and cautions.
Two years ago, my daughter REALLY wanted a Prius, so that was easy. My Son is not laser focused on this car type (GTI - hot hatch) so I still have time and some ability to shift the pending sale.