I've hear they have come out with a "shabbos car".. The haskamos are also pending, but the general idea is grama mechanics and " its only a derabonon" + oneg shabbos...
Sounds awesome! I'm so excited
And if you have a really yeshivish car then it's only a ספק פסיק רישא, because it might not start, and it's לא ניחא לי׳, because you of course don't want to be over any issurim, so לכל הדעות it's מותר.
Who needs that? With the Shabbos app we have Uber...
Which, since getting into a car is, I think, 'only' דרבנן, and paying for something, (especially with credit card) is also a דרבנן, it's תרי דרבנן and would be מותר, although you might be able to say much simpler that since it costs money it's לא ניחא, but that would depend on if you are using uber credit.
Disclaimer: if you know anything about הלכה you will realize this not to be true. I take no responsibility if you are, מחלל שבת ח״ו.