Ahhh fathergoose...I feel your pain!
My wife was none too happy with my decision to add a fourth car to our stable that lacked both the requisite number of wheels and seats to accommodate a family of four (I have a 2 year old and a six year old). Ultimately, I invoked "executive privilege" and just ordered the damn thing!
Nevertheless, let me assure you that your wife still won't like the car even if you add a titanium roll cage! Much less a "plexiglass roof".
Ultimately I don't think any type of fully enclosed roof will work well with the M3W as the car has no way of ventilating the cabin (no AC, no air vents, nothing...)
In such situations, I find it best to ask for forgiveness rather than permission. Remember, this car is still far cheaper than a mistress!
