Our 22 week old springer puppy is growing and eating well and is very fit. The only problem we have (other than the normal puppy things) Is he doesn't seem to associate walks as been fun. Show him his lead and he hides. Once out he is fine.
His first trip in a car he was sick, since then has been fine, could this be why?

It is possible he has associated the lead with being sick, do you have the lead on him while in the car?

I personally would try and make the lead something positive. Just put it on him and then give him lots of treats, or play with him with a toy while still inside your house.
Take the lead off and just go about your day.
Repeat this several times throughout the day, just put the lead on, reward and then remove it.
It won't take long before he associates having the lead put on with something positive coming his way!