Roof bars, boxes and bags

[Looby]

I've got a newish car which has roof rails and I was looking at buying a roof bag for occasional camping trips.

I was looking at getting a roof bag that just fits to the rails but bloke in Halfords said you have to be really careful with weight as the bag will be rested on the roof.

I wanted a bag partly because they're cheaper but also for storage as we don't have a shed or garage, a box would have to be stored in the spare room.

I've looked at different options online but it's all a bit confusing.

So tell me:
1. Roof bag on rails but keep it light?
2. Roof bag but get bars so they take the weight?
3. Roof box and bars?

 

[Bahnhof Strasse]

My b-I-l has a bag and it attaches to bars, but bottom of the bag rests on the roof as it is not rigid. Don't know if they are all like that but he has to be careful not to put really heavy stuff in it or it will damage the roof of his car.

He got it for occasional campaign my trips too!

 

[weltweit]

I don't think I have seen a roof bag ..

 

[not-bono-ever]

If you are converned about damage to your wheels, the get the cross bars to minimise contact - they will give you something to attach the bag to and hopefullykeep the bag off the roof- the aero bars are Ok with wind resistance and shouldnt make a massive difference to your MPG . We have a 500 l top box and it is a faff to take off and store

 

[Looby]

Yeah storage is the main problem, they're so big!

Halfords have these two.
Summit Foldable Roof Bag/box
Bermude Flex Folding Roofbox
Once I've bought the bars as well, these won't work out much cheaper than a box, bars and fitting bundle.
I can find cheaper online but am a bit nervous. I don't want to fuck my car up after I've spent a fortune on it.