Hi, I have a rescue collie who I have had for four years (he is probably about 6 years old now).  He has always been erratic,  barking, and obsessed with the car, to the extent that he would rather sit in the back of the car than go for a walk and when I do eventually get him out he runs back to it.  We have always had problems with him but have tried to persevere and show love aswell as teach him our way of life, however lately he seems to be getting worse. He will not leave the car, or when I try to force him out he will bite me, scratch me, and he barks and trembles in the corner of the boot, acting a nervous wreck. This is really starting to get me down, especially when he turns against me, I feel like he is not happy, but I do not know anything about his past, i.e. whether he has been bably treated etc. I dont know whether I am being cruel keeping him, because nothing I seem to do makes him happy.  In contrast I have a Golden Retriever who is the happiest dog anyone could ever wish for. 
I was just wondering if anybody has any suggestions or advice for me as I want to do what is best for my dog, not just for me.
There are many other problems with him, however this one seems to be getting worse.
Thankyou in advance for any replies

Hi Guest,
I really think you need to get somebody who can look at the dynamics of this relationship from a distance.  You could try asking your vet for a referral to a member of the UKRCB or the APBC (insurance companies may cover the cost).  Alternatively, you may find a local member of the APDT who has an interest in behaviour.

Hi Guest,

Digger's advice is definitely the best way forward - it takes an experienced trainer, able to "think dog" and sensitive to reading a dog's body language etc (which is basically all a behaviourist is ;) ) to work out the why's and how's of complex and long established behaviours.  As owners we are often too close to a problem to read the signals accurately and need an outsider's eye to see what ways WE may inadvertently be exacerbating a problem.

I'm not attempting to profer a solution - Digger's covered that ;) - just wanted to say I wish you well in resolving your boy's issues.  You clearly have a special love for him because you gave a two year old dog with existing problems a second chance and have done your best to work with him for four years - and so it must be very upsetting to hit obstacles that you're not able to work around :(  You've already done more than many people ever do by giving him a place in your heart and your home and I wish you every success in finding someone who can help you both enjoy each others company even more.  Good luck and please join up so that you can post in future to let us know how you are both progressing.
very best wishes,

Teri :P