You need a light car cover then. Tonneau's are non-existent anymore (NA/NB Miata had them OEM: last car I can think of designed for one).
Personally I would not leave the top down 24/7. This top is very tight and there are unfortunately more then a few people who have had rubbing issues at pinch points.
You want to put it up at the end of the day to stretch it back out and avoid it being in permanent pinch mode, IMHO.
Our 2010 is doing well, about 45K miles on it and plenty of top up/downs.
- b