Hi,
Personally I would want a rear wiper.
I'm fairly sure that the UK specification (C16) 996 came with the rear wiper as standard.
The 997, I'm equally as sure, didn't and was an option.
I think it depends on personal circumstances, personally.
My car is normally parked in the garage, but occasionally it is left on the drive.
The drive is a bit awkward to get out of (on a hill, reversing up to a narrow private road)....so I need rear visibility to get out!
If the car has been left outside, I usually find I have to clear the rear window in the morning. I could of course walk around the back of the car, but when you're running late for a meeting, it's easier to get in the car and push the rear wipe button!
Apart from this, unless I'm in stationary traffic, I rarely use the rear wiper.
I personally think the 911 looks a bit funny without a wiper and cheapens it a bit, but that's just my opinion. ie. looks like you've struggled to pay out the 60k in the first place and had to skimp on the £200 rear wiper!!
Cheers,
GD