Sgt.Kanyo

No, there's no need for any scripts.
 
What I usually do, go to pc/data/maps  place the actual map files there (it's a folder that contains .wpl, .img and .ide files), then I open the mod's gta.dat file, look for the IDE lines, copy those into my own gta.dat file into the last IDE section, then copy the IPL lines, paste them into my own gta.dat once again in the IPL section at the bottom, then save the file. Now I copy the images.txt lines from the mod and place them into my own images.txt file and hit save. Afer that I'm all done, in case they didn't mess up the gta.dat or images.txt lines (some mods don't have the path correct).
 
Anyway do you have more then 1 GTA on your computer? Because if so, the problem could be, that the game is using the original copy's files. That's my last idea what might be happening here.

Yeah it's probably a bad collision. If it's a game breaking bug for you, you could try my CHP Ford PIU:
'?do=embed' frameborder='0' data-embedContent>>
(make sure to use the settings and handling though)

If you fire up vehicles.ide you can see a column called "DefDirtLevel". According to the first part of the ide file:
# 0.0  -> dirt range is <0.0; 1.0> (full range - default)
# 0.5  -> dirt range is <0.5; 1.0>
# 0.75 -> dirt range is <0.75;1.0>
 
So if you edit all the cars to have a DefDirtLevel of 0.0, it'll more likely spawn clean, I believe this won't make all the cars spawn clean, but most of them will be.

Yes indeed it's the visualsettings.dat. If you want to use the visualsettings.dat that came with icenhancer, then I suggest you open visualsettings.dat, find these lines:
 
# Other emissive lights            
car.defaultlight.emissive.on    60.00        
car.defaultlight.emissive.off    0.0
 
And you need to change this "car.defaultlight.emissive.on" value to a higher number. I'm guessing it's on a low number right now. You might need to use something like 100 to get a nice strong effect.

Yeah I think I can confirm now that this bug is related to my GTA IV only. I don't think a reinstall will fix this, however I did find a kind of solution.
This only happens in multiplayer I might add that.
First of all I tested it in EFLC, SP and MP, works flawlessly, no problem at all. Then when I go to GTA IV, it works properly in SP, however every MP game I join, even if I host my own server this bug occurs. The "fix" seems to be that, I have to disable then enable the traffic and walking peds with the simple trainer (options, 2nd page, enable/disable cars and enable/disable peds), after that I put reloadscripts into the console, and voila, lcpdfr works just as it should be. I'm running pretty much the same mods in both of my games, except I got a CA pack in EFLc, and NYPD in IV, so I really don't understand what might be causing it. Anyway if anyone has a similar problem, try this method.