What is the slowest car to use when testing in custom races?

[GTEnthusiast9]

I have saved a custom race setting for testing different fuel consumption and tyre usage (among other things). I can only do this via a custom race, otherwise I would just use a time trial. So I have set the number of cars to 2 and I am trying to work out what other car is best to use that will move the slowest along the track and essentially not get in my way while doing test laps?
I have tried the Fiat 500 gave it maximum ballast, restricted its power down to the minimum but even when testing a 700PP car the cheeky bugger still manages to get about halfway around the track. This is a problem because I need to keep watching where he is so that I don't accidentally collide with him in dark tunnel or after a blind turn.

Are there any other specific tune settings I can use to make this car even slower? My next guesses are to do something ridiculous like maximise camber angle and toe in to make it impossible to turn. Any suggestions?

 

[Meythia]

I think it would be easier to give the AI the same car and yourself the largest headstart possible.
Should be taking longer to lap it this way instead of having the Fiat Brick on the road.

 

[eran0004]

Did you try manipulating the gear ratios? I’m thinking you could do some pretty mean things to the poor Fiat by making the gear ratios absurdly tall.

 

[GTEnthusiast9]

Ok I've worked it out! I bought the Abarth 595, max ballast, min power like before, but then I maxed out the camber angle and toe in, lowered ride height to maximise wheel rub and then made the gear ratios as long as possible. I did a test on deep forest raceway and the poor dude couldn't even make it up the tiny hill on the straight, started sliding backwards and then stayed pretty much in the same place for several laps. Just for fun I painted it fluro green so I didn't miss it