And she stopped feeling arm and shoulder pain from propelling it long ago. Nevertheless, all it takes to remind her that she's physically disabled is something as simple as a kerb that's too high.
But there's one place where the 46-year-old German, whose legs have been paralysed since she suffered a herniated disc, is as mobile as someone who's perfectly healthy: behind the wheel of her MINI, which she accelerates and brakes using hand controls.
"To me, driving means freedom," she says.
And she wants other people with disabilities to enjoy this freedom to the fullest extent possible.
So she developed, with the support of her employer, Munich-based carmaker BMW, what she says is the first driver safety training course for people with a physical disability.
The aim is to impart the competence and confidence they need for safe driving.
"No one wants to be in an accident, of course," says Schmidt-Kiendl, who is one of the course instructors.
"But we've got to be extra careful and also think for others, because the disabled often can't free themselves from a car without others' help."
She may have found an important niche, because "more disabled people drive cars than you think," she says.
Making this possible are car modifications that compensate for the driver's disability, notes Achim Neunzling, founder and chairman of Germany's Association of Disabled Car Owners (BbAB).
They include an extra ring on the steering wheel to replace the accelerator pedal, and a hand lever for braking. Wider doors and lifing mechanisms for wheelchairs, and even complete refittings, are further options.
The modifications made for Janis McDavid, a 30-year-old motivation trainer who was born without arms or legs, show how extensive they can be.
He rolls his wheelchair into the rear compartment of his Mercedes-Benz Sprinter via a ramp, climbs behind the steering wheel and operates the vehicle with a small joystick that he clamps under his shoulder.
He says he's driven more than 300,000km this way.
These vehicles - some of which are standard models while others, like McDavid's, are bespoke solutions in the extreme - are provided by automobile retrofitters and car rehab companies.
ADAC, the German motorists' association, lists more than 50 of them in car-loving Germany. In addition, some automakers offer disabled-friendly modifications by custom order.
Of course, not all adapted vehicles are as expensive as McDavid's, which cost a six-figure sum. "But just hand controls for accelerator and brake, and a PRN satellite, will quickly run you €7,000 (RM34,000)," says Neunzling.
The latter is an ergonomic grouping, around the steering wheel, of controls for things such as headlights, windscreen wipers, turning indicator, hazard lights, rear window heater and horn, allowing their operation without having to remove your hands from the wheel.
Disabled persons must not only overcome physical and technical obstacles to drive, but plenty of bureaucratic ones too. "As varied as physical disabilities can be, so too are the legal principles and individual regulations meant to make autonomous mobility possible for everyone in our society," writes the ADAC in a text providing advice on the subject.
Schmidt-Kiendl puts it more starkly: "You've got to look for a long time before you find the right contact person, and then you have to do lots of paperwork before your disability is entered in your driving licence, and the adaptations in your vehicle registration document. In the best-case scenario, you can also find someone to pick up some of the costs for it all."
According to Neunzling, carmakers will often grant disabled persons rebates upon presentation of their disability ID and in some countries people with disabilities of certain grades are either partly or fully exempt from the motor vehicle tax.
But even if this is the case, it's rarely enough to cover the extra costs that disabled drivers incur.
