I have tried to find information on hiring a car from Khon Kean airport and the only wed site i can find is Avis UK and there prices are crazy does any one know if avis or budget have thai wedsites

Both do -

http://www.avisthailand.com/home/guide2renting1.htm

http://www.budget.co.th/

The Budget one doesn't work (for me at least) if you are starting and finishing your journey at different locations. I gave up on them

I have been looking at http://autohirekhonkaen.cheapcharlies-kk.com/ , very efficient response times to emails & plan on booking with them as they have a better selection than avis but this has just reminded me, I haven't actually booked a car yet for next week so I'd better get a move on!!!

There's a car rent place opposite the Sofitel. Can't remember the name of it. I'm sure the prices are more reasonable than the multinationals.

Packpao

Try travelsupermarket online very reasonable

Packpao, thats the same place I linked to. We used them this trip & they were great, lovely new pickup, pickup/dropoff service from the airport, full insurance. Is an English guy called Richard who does all the correspondance & colleciton at airport, I would recommend them to anyone.