I didn 't feel a high downforce...
This car slides like a regular car. He has to stick to the asphalt. Although to be honest, I didn 't remember his behavior in GT6 very well. You said "with ridiculous power..." And I remembered that there were several Redbulls X in GT6, including low power ones. For me, RedBull X is RedBull X2010 (RedBull X1) from GT5. These are two quick laps at Suzuka vs. Fettel

I still remember perfectly how it attack turns into full throttle as it holds onto asphalt. And let Granturismo not be the most realistic game - RB-X made an impression.
And this mod made no impression

But as I said - when I tried it, I thought it was the most powerful RedBull, I just forgot that in GT6, there were different versions, including weak ones.