First the more simple things, tomorrow I'll write a bit more about those ideas. 
Well, wrong URI error probably means the address you entered into a configuration file does not have correct recognizable form. Can you post here the error lines from Airio.log file? That would give me a hint what specific item it concerns, and we can see why the entry is not being accepted.
What Bunder shown to you was correct, restricted cars often need time adjustments. However if you're using high restriction, you are basically creating a new car type. For that case the best solution is to define custom cars. Some people use for example UFB = UFR+45% or FZ2=FZR+20% intake air restriction.
Once you define such custom car (in TCD file you'll find the above examples), then you gain virtual new car type. Airio will keep completely separate stats for such car, so that you may have in one instance UFR and UFB cars stats kept separately. You may disallow using unrestricted cars, group custom cars into categories, etc. do anything with them just like with standard LFS cars.
My opinion is that custom cars are one of the best Airio features, not used much though. Check out for example the Ready2Roll GT2 Racing server, there is a GT2 category completely separate from standard GTR cars. Try joining with GTR, see what it says, try using GT2s, see how custom cars are handled and reported, try using some car commands, such as !sb or !pb or !pi once you make a few laps.
Well, wrong URI error probably means the address you entered into a configuration file does not have correct recognizable form. Can you post here the error lines from Airio.log file? That would give me a hint what specific item it concerns, and we can see why the entry is not being accepted.
What Bunder shown to you was correct, restricted cars often need time adjustments. However if you're using high restriction, you are basically creating a new car type. For that case the best solution is to define custom cars. Some people use for example UFB = UFR+45% or FZ2=FZR+20% intake air restriction.
Once you define such custom car (in TCD file you'll find the above examples), then you gain virtual new car type. Airio will keep completely separate stats for such car, so that you may have in one instance UFR and UFB cars stats kept separately. You may disallow using unrestricted cars, group custom cars into categories, etc. do anything with them just like with standard LFS cars.
My opinion is that custom cars are one of the best Airio features, not used much though.
Check out for example the Ready2Roll GT2 Racing server, there is a GT2 category completely separate from standard GTR cars. Try joining with GTR, see what it says, try using GT2s, see how custom cars are handled and reported, try using some car commands, such as !sb or !pb or !pi once you make a few laps. 
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