If you're talking about undoing the big central nut that holds the wheel bearing on the stub axle then yes, you're going to need something substantial. I took Becky's hubs off when overhauling her rear brakes. It can be done with the hub still in place but makes things much easier with them off.I might invest in a reasonable bar as I have to look at the rear brakes on teh Pandas at some point. Maybe I can find a second hand one. I dont suppose it will be getting a great deal of use. There would be no pint trying my little impact gun on the rear hubs as they will be done tighter than it t can go.. All this torque remonds me of my last company Vectra. They did a service and did the wheels up so tight I turned the crank handle whhel brace until it looked like a cosrk screw before resorting to my short breaker and 5 foot of scaffold pole. Even that was taxing. We had a few word and they unwillingly supplied a new wheel brace. Just as well I check these things or I could have been caught out out of hours in the middle of nowhere. This reminds me I need to undo and re torque the wheels on the new Panda. (which is still changing names... will it be Daisy?? Not really a name for a Panda I think. It needs something muscular lol) Im actually expecting this to be good as everything else bar the duckbills has been. They have even treated the rusty air intake bracket under the bonnet!
I've written very recently, somewhere on the forum but can't remember the thread, about helping my neighbour identify a broken rear spring on his elderly Merc. We needed to remove a rear wheel to get a better look at the spring pan and my old Britool power bar wouldn't look at it. The bolts were so tight that I had to jump up and down on my new 600mm long Clarke bar to get them broken free. My neighbour's a very "practical" chap - he's a fireman - and knew how to jack the car up but he wouldn't have had any hope of changing the wheel if he'd had a puncture. The alloy wheel was also seriously corroded to the hub and took us about 10 minutes of wellying into it with a club hammer and a bit of 4 by 2 to protect the wheel before we got it off. I'm sure the other 3 wheels will be the same and I've - perhaps foolishly? - offered to help getting them off and, after a good clean up, slaistering a bit of anti-seize on the hubs before reinstalling the bolts and tightening them "properly".
I think the tyre fitting places are becoming more aware of this problem - over tightening wheel nuts I mean. We've lived in this house for about 40 years now and I'm well known locally as someone who "tinkers" with cars consequently neighbours tend to arrive on the door step when they've got car troubles. Helping people undo overtightened wheel nuts used to be quite common but, now thinking about it, it's been a while since I've been asked to help someone with this.