k4rt0ff3lsupp3

Your topic has been moved to GTA V Support, this is not LSPDFR related.
Please post in the correct location in the future.

99% of the time, the models are locked. Then there's nothing you can do about it. I'd spend some time looking into all of the models that don't have LODs and not using them. Find a model that does have complete LODs.

And one thing, please, please, please... make LODs for all the cars. That means, L1, reduced polygon count, L2, even more reduced, and so on. Here's a reference page.
http://www.accuratestudio.com/thread/99-setting-up-vehicle-lod-models-properly/?postID=350#post350
Not using LODs on your cars makes them very unprofessional and run horribly in your game. It's extremely impractical without them.

thx for your advice man  ;)

Judging by the floods of comments I see all of you are suddenly discovering how essential these mods and my hundreds of hours of work are to your LSPDFR experience 
As I'm currently a full-time student, I need to do a lot of work and am thus very busy, on top of which I need to earn money to pay all the stuff I need to pay - which is quite a bit.
I'll update as soon as I can once I get all of that out of the way and get enough money to pay for this month. If you're able to please consider hitting the donate button above (or click here) to help me out here (this comes with certain rewards too)
Cheers guys 

Go into the .ini folder for Police Radio, and scroll down until you see http://prntscr.com/cre2jf, [NOTE: In that screenshot, CORSPEEDO will be SPEEDO.] Now, replace "CoronerVan = SPEEDO" with the name of your new coroner van. [The .ytf/.ytd's of the vehicle you installed into openiv]
That should help.

do you have updated your mods folder in OpenIV??
had the same issue a few patches ago and had no idea,open OpenIV,go on your "mods" folder,on the right there is a button to update your folder because the game is patched ;)