Alright, if no-one else will, then I'll play the Devil's Advocate for a moment..... Have you thought that even if your wife
would read/use a map like that, having it
ON your back while ryding will make it pretty much impossible for her to read well
while you're ryding!! :shocked:
Consider how close she's going to be to your back when she's on the pillion seat & how much space there is between you & her?? Do you reckon there's room there for her to read anything??
And if that's not enough, consider how well you'd go yourself, trying to look
INTO your own belly button, cos I reckon that's pretty much the sort of thing your wife is gonna have to do to read anything on a map that's strapped to your back!! :dontknow:
Oh, & what about her reading glasses - if she doesn't need them yet, the results in the threads on 'How old are all you Spyder ryders' suggest that there's a good chance she's gonna need them soon!!

pps:
And finally, have you asked your wife if she'd like to do this?? I don't think just springing it on her & saying 'now you can navigate while we are ryding' is a real smart move - it's sorta like blowing your first wedding anniversary by buying your new wife a flannel nightie AND an new iron & ironing board, & then when she doesn't look too happy about it, suggesting that the flannel nightie will help keep her warm when she's up early ironing your shirts on those cold mornings before you head off for work!! It's just not a smart move on so many counts!!..... :shocked:
So if you must, at least discuss it with your missus first!! And be prepared for the fall-out! nojoke