Rechargeable Nitro

Rechargeable Nitro — a mod for the PC version of Need for Speed: Underground by author Cishy that adds automatic nitrous recharge. As in NFS: Most Wanted, the nitro tank gradually refills itself, so you can spend nitrous during the race rather than saving it for the final sprint.

What the mod does:
* enables continuous automatic nitro replenishment;
* works as an ASI script (dinput8.dll files and contents of the scripts folder).

Author: Cishy.
Source: https://nfsaddons.com/downloads/nfsug/tools/11559/rechargeable-nitro-for-need-for-speed-underground.html

How to install

1) Open the root folder of Need for Speed: Underground (where Speed.exe is located).
2) Unzip the archive and move all files and folders from it to the game root: dinput8.dll and the scripts/ folder (it will merge with the existing scripts folder).
3) Launch the game — nitrous will be replenished automatically.