If you are building a new garage surely that would be the time to sort out the drainage problem from the lane. Can't you put a driveway drainage channel in the ground directly in front or the garage door opening and drain any flood water away? Done correctly this will cope with all but severest flooding. You can dig a soakaway or some local authorites let you drain surface water in to the main sewers. Raise the garage floor from the drive height an inch or inch and a quarter and you wouldn't even notice it, but this would also help if you're only getting a couple of inches of water in the drive. It's difficult to be of more help without seeing the site but from my experience, when you are building new from scratch, you can always do something. I am a carpenter/builder and have done a lot of this type of work, never had any problems. Think about it before you start, if you don't know what you are doing, employ someone who does and you shouldn't have too many problems. Hope this helps a bit. Oh by the way, if you need any bits for your car just pm me.