Not true - Pioneer do a set that 'hot swap' called the
TS-Q131C. Having said that, I've got them in my 182 and wouldn't recommend them as a one stop shop solution. If you're keeping the standard head unit, you'll be disappointed if you like loud and bassy. Someone suggested to me to amp the speakers, but not sure how much difference that'll make. I ended up snipping the wires to replace the back ones anyway and really wish I'd just done it properly instead of looking for an easy option the first time round.
You can pick up a wire stripper from the likes of b&q for £10 that's a useful tool anyway. It really isn't hard at all unless you're wanting to replace the wiring with any wiring provided. I personally opted to use the renault wiring (don't know if this really makes much diff with the standard headunit anyway!) rather than the wiring that came with the speakers. Only 'hard' part about it was I had to recycle the spade connectors off the ends of the provided wires and fit them to the wiring already in the car. Whilst a little fiddly... really wasn't hard at all. You could avoid this by getting speakers that don't require spade connectors and instead have screw down fittings that clamp the bare end (After stripping) of the wire.
It might sound like a lot more effort and hassle, but it's not really. Talking an extra hours effort really, though I'm sure I could do it again faster now I've done it once! The biggest extra effort is being unsatisfied, having spent near enough £100, that could've gone toward better speakers in the first place/new head unit.