[tirwin]

Do you own any of the "coffee table" books on Porsches or the 911 in particular?

You could point out the 50th anniversary of the 911 that just happened recently.

It might help your case to state the number of cars built in your model year vs say GM or Ford. Maybe express that as a percentage.

Were 911's still hand built in your model year? If so, point that out.

The 911 has only been built in Stuttgart, right? Goes to the point that it is not mass produced.

I think Hagerty has a tool on their website that lets you see market trend for your year/make/model. Maybe you could point out there is an X% increase in prices over Y years which clearly shows these cars are collectible.

My advice is to have 2 or 3 fairly solid points up front and then have the rest in backup. If you convince them quickly don't sell past the close.

You're likely either dealing with someone who will see $$$ signs in terms of tax revenue or someone who is going to rubber stamp whatever you say because a) you showed up and b) you have a pulse. Read the room and see if you can figure out what you're dealing with before making your argument.