Frankly, I think you’ll find it’s a fifty/fifty world, half of women love the the car, and the other half hate it. Mine moved it once (I was in bed ill) and she wanted to go out in her car. She threw the keys at me, and said “In bed or not - you can bring your B- - - - car back in, I refuse to drive it any more”. Another time, not long after this, she was ill, and she asked me to driver her to the doctors. Complained all the way, “it’s too stiff, why does it thump so much, it’s noisy, Do you have to drive so fast? (25mph!) I don’t like it”. Never been in or near the car since. Call it a mindset, or a female point of view - what ever!
On the other hand, I’ve met young ladies who love their cart as much as any man. and older ladies who only get to use the car (supposed to be theirs) during the week, while Hubby takes it over for the weekend. Inevitably, it’s main use is a shopping trolley, but they still enjoy it when they can. With multiple children, not much use for school runs, so you don’t see many used for that purpose.
Male drivers have a different perspective to most women (not all), who generally prefer the soft springing and comfort of the average family saloon, where a male sportscar driver expects a firmer more positive drive in a car mainly intended for men. A male passenger will grin with delight when cornering at speed, while a woman will shriek and reach for the nearest thing to hang onto, as her sense of balance and security is threatened. Hence the fairground comment.
In the days when a car dash was made of steel, that was one favorite place to mount a grab handle, but the lightness and integrity of an MX5 means that even the door has limitations (IMHO) as being a safe and secure place to mount one. The dash is too far away to be of any use. A four or five point harness would hold your wife more securely, but she will no doubt object strongly to a feeling of being shackled as such.
All things considered, your wife is really saying she hates your car, but she is too diplomatic to say so, knowing that the alternative is to stay at home while you enjoy it yourself. A tight seat belt should hold her in place, but if she objects to that, not much hope for a safe resolution to the problem.
Before I get jumped on by some well known lady owners in the Club, let me say that there are some well known really keen lady owners out there, who not only drive their car for fun, but in some cases race it too, so I’m not slating the fairer sex, but willingly acknowledging that they are there. Fair dues. We admire you all.