Performance issue, very bad FPS and FPS drops

Guys..Now things are getting crazy but I think I'm a step further to the origin of this problem:

I found something out where the overall performance is much better beside those areas where the framerate is crazy low.
Beside these areas (where I posted the screenshots some pages before) I got constantly 30 FPS. Not even 1 drop in the Framerate.

Then there are the areas where the drops are huge. The areas with my screenshots you can see on page 10. Lets take for example this area: http://abload.de/img/nfs142013-11-2719-50-helgz.png
My Framerate in this area was always 15-18 FPS. I was able to manage to reduce the drops to about 27-29 FPS. That's about 10 FPS more. But it didn't work every time. I didn't find out why it works sometime and the other time not. For example I was driving there and had no big drop in the framerate. Then there was a Host-Migration. On the new host I drove to the same location and I had these drops again. 
I also restarted the game sometimes to check if something changed. Sometimes I got the drops, sometimes I didn't. One time I had a huge rendering problem of objects and textures. The drops of the framerate at these locations were crazy. Then I restarted my computer, tried everything again, the rendering worked fine and no drops in the framerate at this location again.

This is one of the other locations I mentioned on page 10 where I had huge drops of the framerate: http://abload.de/img/nfs142013-11-2720-09-i5kyf.png
I experienced no drops in the framerate everytime I was there. Not even one drop!

Then there are other places like the harbor: http://abload.de/img/nfs142013-11-2720-03-1icui.png
I experienced the same drops in the framerate again. Also with restarts I wasn't able to experience the improvements I was able to experience on the other places.

So to get that together: The overall performance beside the "huge-drop-areas" was great! Not even one drop.
In the areas with the huge framerate drops I was able to improve the framerate on some locations.  At some of these locations the drops weren't as big as before at others there wasn't even one drop for me. And sometimes at some of the locations the performance was as bad as before (but not all the time!). And then there are areas like the harbor where I didn't notice any differences.

So here is what I did:

I installed the full version of Fraps. If you don't know that: It's a program to create screenshots or videos of the game you are playing. After that I rebooted my PC and started Fraps after the reboot. 
Then I opened the "Movies" section of Fraps. I set the video capture settings to 30 FPS. Because the limit of the game is at 30 FPS.

I started the game left the hide and started to record a video. That's it.

The end result: some major improvements in the framerate that worked always for some locations, sometimes for other locations and not for even other locations. Beside these locations there was not even one drop in the framerate. And...yes...I got a 40GB video file xD

Next I wanted to know if the framerate is better if I set the FPS-cap of the game to 60FPS with the help of the command line. I also used another command so the game runs at 60FPS in normal speed (like it does on 30 FPS without the commands). Also I set the video capture settings in Fraps to 60 FPS.

In the world beside those "huge-drop-areas" I got about 50 FPS in average. Sometimes even 60, sometimes 45. And here and there just 35-40. A big noticable improvement! Without recording a video I'm not able to reach more than 40 FPS.

And the "huge-drop-areas"? The same framerate like the try with 30 FPS and recording a video. There are areas where the framerate droped to 35-40 FPS (which is okay if you stay at the 30 FPS limit) and there are areas like the harbor where I still get 15-18 FPS.

So lets get a conclusion: I was able to reach 50-60 FPS at certain locations while recording a video in 60 FPS with Fraps. There were drops to about 30-35 FPS. That means that the game is still pretty bad optimized. That are drops of about 25-30 FPS. You won't recognize them if you play on the normal 30 FPS limit. But there are huge drops. So the game is poorly optimized!
The other conclusion is that I was able to get a huge improvement while recording a video. I have no idea why. I think it has something to do with the hard coded framerate limit in the game engine and the framerate limit Fraps uses. But I'm not sure.

I think we hav to investigate more in this direction!

And now give me your opinion! ^^