Roof Rails / how strong?

[an.da.ru]

Hello,

I am new to UK passats, and have just recently bought a 2004 2.5 V6 Tdi estate. Its a great car and really enjoying it for family trips.

i am looking to go on some long road trips holidays over the summer and have come across these electric pop up roof tents here is a link to a picture of one of them

https://s-media-cache-ak0.pinimg.com/73 ... 0e900d.jpg

we were thinking to have both myself and my wife with our daughter up there, so i would imagine it could be around 160 to 180kg or so including the roof tent

The roof rails i have are the chrome option.

So, before i look into buying one, it would be great to know if there is anybody who knows how much weight can be put on the roof rails of the 2004 Passat estate [chrome option if that makes any difference?]

Any help or knowledge on this questions would be greatly appreciated.

Thanks,

Andrew