Irontis

You're using LSPDFR version 0.2 RC7. The plugins you want to use NEED LSPDFR version 0.2b to be able to play the scanner audio.
Update your copy of LSPDFR and this will fix the issue.

Okay,  now we have an idea that something else is also not set up right.
 
I don't like it either,  but the only way to find the problem is reinstall GTA IV with no other mods, nothing.
 
When GTA IV is ready,  install ELS 8.0 and let it copy everything over.   You could install 1 ELS car just to test that it works and how it looks.
 
After you are happy with ELS working,  install LCPDFR 1.0d and let it copy/replace its files.
 
 
For some people,  there are sometimes problems with ELS + SNT key binds.  Try installing Simple Native Trainer after LCPDFR.
 
Read the 2nd post from (CouthInk4),
 

 
 
If all this works okay,  you can start adding whatever extra scripts you want.  
 
 
You want to make sure the basic parts (GTA IV, ELS, LCPDFR) are done correctly and test them one at a time.  If you still have problems,  it makes it easier for other people to help out if there are fewer things to look at and diagnose.    
 
 
Good luck.