I have a few questions. So really here goes
I need lenses (yes maybe more than 2 lol)
But i am unsure whats good etc.
i have a nikon D50
kit lense 18 -55 and the 200mm lense as well

Anyway here goes
i need a good lense for airshows and rally driving etc
so it must have a fast reaction etc and not spend ages auto focussing etc.

Also what filters would you recormend as well

Next i am going to a sunny country later in the year lanzarote. So what filters would you also recormend i get
polariser, skylight

since you have the 200, telephoto is pretty much covered.

A wide angle would also be essential. I have the Sigma 10-20 and it's excellent; although a bit pricey ($500). You can find cheaper models though.

Another thing I would recommend is to get rid of the 18-55 and go for the 18-70. The 18-55 is in my opinion an extremely crappy lens.

In terms of filters, you will need a circular polarizer and maybe a neutral density filter. Neither of which should cost more than $100.

200mm lense is not good enough for things like going to F1 races depending on where you stan you will never get in close enough on the cars to get a decent shot, i read a article from the words best F1 photographer an he recommends a 300-400mm lense minimum. Im currently saving for the sigma 170 to 500mm lense which will cost around 500GBP

While you are absolutely correct, does tunafish sound like a photographer who would actually use a 300-400?? Please be mindful of what advice you give to whom.

It all depend on where you will sit. The distance between you and the subject. Sometimes, 300mm is enough, sometimes it isn't
However, because you want to shoot fast moving subject, you will need a fast lens to fix the subject in S mode. But by doing this, you probably won't have enough light to have a correct exposure. That's why a f/2.8 lens is often required. But unfortunatly, these lenses are not cheep.

My advise would be to buy a Sigma 70-300mm DG APO at first and see what focal you need. This lens is cheap and known to be the best for level entry users. Later, you could save money to buy a Nikkor 80-200mm f/2.8 , Sigma 70-200 f/2.8 , Nikkor 300mm f/4

For a kit lens, it is actually pretty good. Definitely better than the Canon kit lens. I bought the 18-55 to get started with my D70s and so far I am pretty happy with it. Sure, there are better lenses but this one really has a bang for the buck factor that makes it a nice basic lens to start out with. I have noticed a lot of my shots are crystal clear. Sometimes it's a pain in the ass to focus but my main problem is that I am not all that used to a DSLR yet.

i am thinking of getting a 170-500mm F5.6-6.3 DG APO (86mm)
i spoke to a few people in jessops and other photo shops and they said for what u want the 500mm will do
as they were saying why get a 300mm when you know you will be looking to upgrade etc.

The aperture on that lens, wouldn't allow for all that too great freeze shots..

As Floyd has suggested before, f2.8 would be ideal, especially if you want to freeze high speed objects.

Well this guy is one of the worlds best F1 photographers and he uses the Sigma 170-500 which i have just purchased. Go take a look at his photos, he seems to manage with that lens perfectly.

http://www.photocritic.org/2006/f1-formula-1-one/