Hi - are there can rental companies in Paros that I can pick a car up in Naousa and return it to the port. Thinking of going to Lefkes/Marpisa on our final day before we head to the port. This would allow us to bringour bags from the Airbnb and see those two villages and then bring ourselves to the ferry without needing to figure out a transfer. Any company recommendations?
Most car rental companies in Paros (if not all) can arrange what you're looking for.
As for renting a car on the islands, it's simple: I use Google Maps, zoom in on the port of Parikia for Paros (and also Naoussa in your case), search for "Rent A Car," and then make my selection.
I've already rented from three different companies in Paros, but only those that don't require prepayment and where you book the car via a form on their website or by email. I've never had the slightest problem. But perhaps you're looking for an automatic car or a more "formal" booking way
After Lefkes, before arriving in Marpissa, stop in Prodomos.
https://maps.app.goo.gl/orc1xbpf7KdnGB2A7
And if you have time, you can then follow the coast south and pass through Drios.
https://maps.app.goo.gl/vd4Pno48cun2X4Un7
And Aliki.
https://maps.app.goo.gl/c9wR73sFxxwetQQS6
This will give you some suggestions about where to stay on your next trip to Paros. :)