Everything has been said already, but only half the comments are good for you - the other half should not be listened to, as they are bad for your photography, like drugs in excessive dosage is bad for your brain.
DON'T start, to make do with smaller apertures, extending your DOF, to overcome your (temporarily) manual focus short coming !
Comments, that you need to practice this (A LOT) are spot on - these comments are good for you - DO THAT!
Not consistently being able, to shoot wide glass on movable subjects is nonsense.
The more you practice it, the higher your keeper rate grows.
With really fast lenses like f1.2 or f1 50mm, there will be a higher trash rate, than with slower lenses.
I started last year with a Leica M6 shooting manual focus - I could not shoot a snail crossing a street at f2.8 at the beginning.
This summer, I decided, to bring only two Leicas to the 24h LeMans, to shoot sports car racing. It was the first time.
The first two hours of the race, I shot digital, to check my learning curve and try out different techniques, I thought out.
It was a tour de force - a huuge disappointment - I was very close before giving up, shooting the race, but doing some of the event, people, etc and enjoy the race weekend.
Somehow though, I didn't give in and it clicked. I found a technique, to consistently focus with the RF, while following the cars through a section, shooting the lens wide open (90mm f2 and 135mm f3.4).
To my initial surprise, the keeper rate was very high (way over 50%), so high, that it was even in the same region, as when using a Nikon D3 and fast tele lenses, hammering away at 8 frames.
You must experiment with different techniques, to find out one, that suits YOU.
… and you don't come around, practicing manual focus A LOT.
I do this basically on a daily basis, while commuting to the office, shooting from a moving car - this helps.
I basically shoot fast lenses on the Leica, while oscillating the focus ring back and forth around RF patch coincidence, getting finer and finer an adjustment, until I decide, to shoot after composing.
I adapt this technique to the time, I will potentially have for a certain shot, choose my aperture accordingly and combine this with constantly pre focussing the lens in anticipation of a possible focus distance for a potential photo (this is important for fast lenses with big focus throw like the Noctilux or 90mm f2 or 75 f1.4).
It is very rewarding, to find your way with manual focus, keep at it and don't give up!
And don't let those f8 shooters drag you into that lazy mode - your lenses helicoids might rust that way!
These cars did not just pass by at a constant distance - they came, closing in or accelerating away from me, while braking into or driving out of Dunlop Chicane at LeMans. So they were certainly not sitting ducks.
On my way to Germany, I bought a 35 Summilux in Paris, which I shot during the whole trip back - I used the same technique on this speeding by train:
Back in Germany, I visited a friend, photographing some of his animals on the farm and also his 1 year old for family shots with a 90 f2 lens. I used my Le Mans technique and I can tell you, the geese were the most difficult thing, to focus on, I ever encountered @ f2. The very active 1 year old though was a breeze by comparison.
Strictly limiting your lens choices is very helpful, as it is easier, to find a good feel for focus throw, lightness of the focus, DOF margin of a certain lens in a certain aperture range, etc.
