Is it me or are the “drivatar” ridiculous on dirt??? It rarely seems too much of a problem to spank the drivatar in the weekly series - unless the series is on dirt!
I do not normally have much problem with the these, even in a stock car, unless the series is mostly off-road - they’re all over uber-powered and an corner as if they’re on rails!
Dirt is ok, it’s the cross country they always seem to have an advantage on
I’ve found in Dirt races that the AI is overgrippy and powerful on the road sections, but beatable off road if you have the right tyres.
Cross Country, as stated above and elsewhere, they have ridiculous levels of grip.
Just to add, your thread title sounds like the slogan for a detergent or floor cleaner!! 
On dirt its usually fine, but on cross country events, jesus, then the AI really soups their the rocket ship engines and just takes off at 300 mp/h and leaves you way behind, especially in the championship races. If its a normal exhibition event, it`s usually easier, but in championships, God help you in cross country.
Meta tunes and meta cars is the only way to win such championships in fh5 sadly.
Cross country events was also the hardest championships in FH4 aswell, with even less traction, rain, and the insanely op Can-Am Maverick, ( when the ai drove it ) winning was almost a novelty, i once lost a 3 minute race with around 15 seconds to a Can-Am Maverick in FH4, i finished second, but the can-am was unbeatable, even on highly skilled.
Oh, it was definitely the cross country event that the Drivatar were vexing me with their abilities.
In the current weekly championship. . . I got past the circuit events easily enough, but that cross country was something else! I finally pulled off a 2nd place in the XC after getting spanked again and again - I had to change to a much better car than I used for two 1st place finishes in the circuit races. Their ability change in the XC. . . just so imbalanced.