Reported sales:
Domain Price Date Venue
calgaryoffice.space 100 USD 2015-12-08 Flippa
cctv.space 445 USD 2015-07-09 Uniregistry
conversation.space 225 USD 2015-05-12 Uniregistry
cluster.space 1,000 USD 2015-04-28 Sedo
Disappointing.
On what basis are we supposed to appraise ?
I think it could be a difficult target group. There are not so many car parking ventures in any given city. It's a limited pool of end users to begin with, and they must be open to the idea of using a new extension - good luck with that.
The large groups use brand names eg. EuroPark, (Park 'N Fly in the US), Q-Park (active in the UK and continental Europe). The small outfits will normally use a geodomain like liverpoolcarparking.com/.co.uk or some variation and that's it.
Just to get a sample of the market, I found only 5 reported sales for the keyword 'carpark' (source: Namebio). That confirms my feeling. Not an industry with heavy demand for aftermarket domain names.
Domain
Price Date Venue
airportcarparking.com 3,001 USD 2016-11-08 Flippa
carparkinggames.org 1,475 USD 2014-01-12 Afternic
nationalcarparks.com 3,386 USD 2013-11-17 Afternic
grittingcarparks.com 2,595 USD 2013-03-04 Afternic
carparking.com 54,600 USD 2007-01-04 DotcomAgency
You are another victim of a Godaddy upsell

I would set the autorenew to off personally. Good luck.