I have recently covered my Eriba with a universal cover and have the pop top down. How many keep the pop top up under cover as I don't know what's best. Found some advice here and have now put the rollers up so the blinds continue to work.

Opinions vary. We have always stored our Eriba covered with the roof down, leave a couple of windows on vent. Move cushions away from the wall and leave the fridge door open. Remember to drain the water and leave the tap open, having made sure the battery is disconnected if you have one. Our battery is always stored inside on a trickle charger.
Having said that someone will probably be along shortly to tell you that they do the exact opposite, there are as many opinions as there are Eribas it seems.

Big Nellie is at home under cover with roof down but some windows on vent / fridge slightly open BUT we also have one of those little tube heaters in her with a thermostatic plug so it only gets switched on when the temperature drops below about 12 degrees. Never tampered with battery / cushions left in and even the bed's made up (if, like in a couple of weeks, we use her in winter we then chuck hotties in the bed - we normally carry little ones with us !!!!).

Apart from that she's left to her own devices though we do pop in every now and then.

My cover is fitted so it's top down for me....

I checked my Pan a few weeks ago and found it was rather wet inside, today was the 1st chance I've had to investigate. What I found was that although I have a breathable cover over it water was sitting on the flat of the roof and getting under the poptop seal, the canvas was then soaking up the water which inturn was dripping inside. So I popped the top under the cover (which was obviously designed for this after I released the straps a little) wiped everything over and ran a fan for a few hours. So locked it up now with the roof up.... I'll check in a few days to see if it's a fix

My 320 is in the dry barn with a sheet over to stop the dust and the top UP