Fresh from my Gauntlet testing I’ve been thinking about what to do next and I don’t know why but I thought this stupid idea up…
Marathon
I have to do 1 run for every single PI point (100-999, X class done in a race vs Tourist AI)
I must use every car in the game at least once (Ford Coupe FE + OPI GT would be excluded though)
I am not allowed to use the same car for 2 consecutive points.
I did consider the Colossus but I don’t think I would be finished by the time FH6 arrived lol
Thoughts?
Let me see if I understand correctly. You’re going to do 899 Marathon runs? You’re going to start at D100 and the next run would be D101 and keep going up 1 PI til you get to 999?
If I’m understanding correctly, I wonder if there are enough cars in the lower classes like D, but I guess since you can use a car more than once, just not twice consecutively, it should work out.
This seems like it would need a lot of planning out exactly which cars for which PI point to use every car at least once and a lot of upgrading of every car to get them at the PI point you need.
It would probably be time consuming to tune each car for their specific PI point so would you just upgrade and then leave the tune stock?
I like this idea. These tests are a good way to keep the game fresh.
You have tou much free time 
As for idea for test: PI balance test?
And now you have two options:
a) you take one car and test different tunes (e,g, stock tires-street-sport-etc.) at one given PI at one track or 3 different (handling-mid-powerbuild) tracks
b) you tune cars so they have roughly the same weight/power with the same compound and the same gearbox - I guess that one is better for handling tracks cause of different drag at higher speeds(?)
I was trying to do that latter one for some WTCC/DTM/BTCC rivals challenge event, but abandoned it. IIRC Audi TTs (all with 1.6 swap) were matched perfectly on power/weight/gearratio/tires sizes and it ended up with ~770, ~780 and ~810 PI cars and very different lap times.
Anyway, IMO some sort of PI balance test would be a much better “timewasting”, but if you want just have fun then go with your “ridiculous challenge” 
my thoughts are that you’re mad
there are some cars that show up +/-1 in terms of stock PI, eg, Jeep Trackhawk is either 749 or 750
Yeah I am not even 10 cars in and ran into this issue, upgraded the Porsche Mission R and it shows as 991 in My Cars but 992 at the top of the screen.
@ziperrPL you nailed it lol, it will just be something to fill in the gaps between the playlist/rivals stuff, already got the D100 one out of the way so what should be the worst has passed already.
@x_ShadowsBane_x I’ll be leaving cars untuned if they look reasonable for the Marathon as is, some may even need downgrades for them to find a PI point where I can use them.
If ever we needed more proof of how bad the Rimac Nevera is I chose it to be the X class car yesterday, 4.3 seconds slower than my 991PI Lotus Evija which is a rubbish S2 car itself (it’s my guilty pleasure in the game though).
there are ten or so, I’d say, where it’s a regular issue, always the same cars - though only the Trackhawk sticks in my mind - very odd; even more odd, maybe, is that when sorting by PI I get the impression that it deals with them as if they were the same PI (hard to tell, though)
I have no idea why it happens, can only surmise that it depends how it’s acquired (bought from autoshow, bought from car collection, won in a wheelspin, reward from playlist . . . )
consistency could come from resetting in custom upgrades then using garage PI or top-of-screen PI, though I’m not even sure about that, think I’ve had two of the same, done a reset on both and they still don’t show as the same PI; could maybe try forcing it by doing an upgrade, say an auto to max class to minimise effort, then resetting - but it’s an arse to do that over and over . . . that stated if you are looking at tunes anyway perhaps not
being a nerd I keep records in an Excel workbook so issues with such details are irritating
related to that, maybe, is this weird thing where some cars have a “remove and flag this livery” thing in the garage but others don’t; resetting the appearance does nothing and this can be on absolutely new cars from the autoshow
just has a feel that it could be related and I realise it’s off-topic
How about using every car, in each available class. This is what I started doing in FH4. I cannot remember if I got bored with it, lost track of where I was, or FH5 came along.
Looks like I may have to consider that instead, currently compiling the full list now and I’m 99% sure it can’t be done, too many big gaps in early D class where I would be repeating the same group of cars, from D100 up to the '74 Celica’s stock PI at D315 there’s only 30 cars I could use, the next car after that is the Transit at D347 and I don’t think the Transit can even be downgraded that far, so 185 unique spots are lost there on their own.
Then all the little gaps from that point on I think make it impossible.
Nice idea I suppose sadly but thought of too late, earlier in the game’s life I think it would have been doable.