check the 'nose weight' of your towbar.

The weight of the rack plus 4 bikes might well exceed it.

Pendle/Thule etc are the ones to go for really.

Mottez are cheap and cheerful. I just happen to have mine for sale! email me for pic,s.

as above the Aiston are immense if your car will take the weight

I've got one of these:

http://www.roofbox.co.uk/scripts/rbvehsel4.php?query=TR536&vptype=&emulate=accgen&qty=1

– very pleased with it – as strong as a Pendle one I had but lighter to carry to the van and a good price too!

Another vote here for the Atera Stada…. Fantastic, and the fact the rack rolls away from the back door/boot means you can still get in really easily. Also if nose weight is an issue this is one of the lightest racks around… Expensive though! http://www.roofbox.co.uk/scripts/rbvehsel4_tab.php/car-accessories/atera_strada_dl_3_to_4_bike_carrier_uk_lights_no_ar2603/njNA_v1HqTo9~w7HCO3kxz3uBtkB%2C~4RYoJEYzTmI

gravelrash – you can get adapters now that bolt onto 'swan neck' towbars and allow the other style to be fitted – not sure if it'll work with a pendle though.

I have the Strada which I think is excellent. The unique feautre is that it slides on a curved arm, away and down from the car so you can open the boot/tailgate, and unlike most others the weight is supported. This is a 3 bike rack as standard, with a 4th bike extension on the back.

What they don't tell you is that to support the weight of the 4th bike, they supply long webbing straps which are supposed to hook over the top of the car tailgate or boot lid. This cannot be used with a hatch/estate with any kind of spoiler (which many cars have these days), and to me negagtes the whole point of having a tow bar rack, having ruined the body work of a previous car with a strap on rack. Two of the cars I've used the Strada on have been MPV and Estate with spolier on the tailgate, and I wouldn't have been prepared to use the webbing straps anyway for fear of bodywork damage.

I have improvised with the webbing straps and put these around the back of the tow bar mount and over the top bar of the rack which holds the bike support arms. This helps spread the weight and stop the rack bouncing around on bumps.

Also, the spacing of the extension bike mount is very tight for the 4th bike – bike 3 and 4 are close togehter. I've found it only suitbale to take my daughter's small 20" wheel bike.

So in summary, excellent rack for 3 bikes, OK for 3 + Childs bike, too small for 4 adult bikes.

I tend to agree with skyhigh re the straps. It wasn't until I opened the box for the 4th bike attachment that I realised the straps were needed.
They do supply a couple of patches of copter tape to protect the paintwork, and my car doesn't have a spoiler so it works ok for me, but you need to check.
The spacing between bikes 3 and 4 is tight but I have used it with 2 adult bikes in those positions- not ideal as the 4th bike tends to lean away from the 3rd at an alarming angle, but secure enough. Better with the smallest bike on last.

I've a very old Pendle. No problems at all with it. I can get it off and on without help (just wriggle it) and it's pretty sturdy – it survived a rolled Discovery moment without a complaint!

older thule euroclassic here. 4 bikes on the back of the zafira no problem. standout feature is the rack folds square which helps with storage. not sure the new ones fold tho.