Have heko on my S4 from ebay. If you get any, ignore the tape thats on them already. its just 2 sided sticky tape and is literally useless for the rears. The fronts dont matter as they are wedged into the sill by the shape. The rears need foam double sided tape (cheap from Halfords). Stick that on, put it in the door and they stick for ages.
I found out this the hard way, when driving along the motorway, one of the rears flew off! replaced, used the new tape, and never had an issue yet.
I find them really useful as I like having the windows down a little rather than having A/C on all the time. Only downside is you do get increased road noise with them installed (windows up or down!)