It's mostly true, even if you KNEW how to set this car up, you would be gaining mere seconds around a track. This amounts to basically nothing on the roads, but will make the car a lot less reliable, higher maintenance etc.
Either that, or you go all the way. This might be a problem, considering how noone in the tuning community has even heard of your car
But with the right skills, I bet you could squeeze at least 50 hp more out of that engine, which would probably be really expensive and not at all worth it :b