I fit our Thule bars at the start of each Spring and leave them on until the 'last camp'. The box comes off after every trip though. Fuel consumption is affected by it, vandals are strangely drawn to this huge thing sitting on top of a car and thieves can't help but wonder, 'what's in the box???'.
They are expensive for what they are, but on the basis that the other option for me was a different car, the box/bars was the right way to go for us.
We bought a roofbox after buying our tent and the basic equipment we needed for our first camping trip and realising there was no way it was all going to fit in our car unless we left the kids behind!
My only advice would be buy the biggest that you can afford and that will fit on your car. We looked at second hand but in the end bought a new one from Halfords. It was cheaper to order on line and then collect from our local store and we paid £200 for a 470l. The bars we paid £80 for online. I would agree it's expensive (more than we paid for the actual tent!) but well worth the investment and it did affect our fuel consumption.
I had this issue as well and did lots of research - the results were:
Roofbox - the best choice but about £250 was the cheapest I could find new. Difficult to find the correct bars second-hand and not a huge number of boxes second-hand either, in my experience.
Handirack and Handidholdall - about £130 but I was put off by some comments saying that it allowed water into the car and the straps can get in the way of your head.
Cargo bag and rack - my compromise; I bought Thule bars for £95 new and a Cargo bag (unbranded) for £40. This way, if the bag is rubbish, I can bin it and buy a box at a later date. However, the bag looks pretty good. I've not used it yet but it is easy to store and seems very well made.
We have a Karrite one (made by Thule) and we love it. Its the second one we've had and I would recommend one. The 470 L is anywhere between £150 and £200 depending on where you look.
Cheers
Alasdair
------------- "If nothing else works, a total pig-headed unwillingness to look facts in the face will see us through." General Melchett
Quote: Originally posted by John Preece on 15/4/2009
got mine for £20 quid off ebay and £30 for the rack. Not bad for 330l capacity
You jammy devil
Rack was brand new and work on cars without roof rails (my zaf has no roof rails. I went and collected the roofbox off a man i bought an electric coolbox for a tenner, a mini oven and the roofbox all for £40! he was gutted and thought i was a dealer (I think thats because of all the camping equipment i have bought since jan!). Still roofbox is all but functional and no cracks or major damage (usual scuffs for a roofbox). But yeah i am realising how lucky i have been - bidding on a nice looking trailer now which is huge (more like a tractor trailer than a car trailer!) - lets hope i win that now!
------------- Camped since 2008 and still loving it!