[Perfectlap]

I would not buy a pre-2009 996-997/986-987 Boxster or Carrera without one or I would have it immediately installed if I did.

There is certainly value in taking care of that hassle before the purchase.
Kinda like buying a house with a new roof vs. one that needs immediate repairing.
Although with this Porsche not every roofer knows how to or is even pertmitted do this job, including the one who built the flawed roof in first place.

But since you are dealing with an insurance company, you know how that goes.
People are easily swayed if you simply inform them of a potentially catastrophic Porsche problem that was never addressed by the Germans, send the potential buyer the Excellence articles on the subject and a receipt of your IMS upgrade. An updated IMS would be a very strong selling point to a second hand buyer if you sell it that way, and it's not like your making any of this up to get the sale.