Hi, Can anybody tell me out there how true this is and is it the same in every puppy, I mean is it guaranteed they will all be as sesnsitive at this period or just in some puppys or a particular breed more than others.

In what way do you mean sensitive.

That they need to have travelled and settled in their new homes by this period if possible as if they had a bad experience traveling at this time in the car they could always not like car journeys.

No I don't think it matters. Provided you are sensible in the way you get your puppy used to travelling. If you have had to collect your puppy from a long distance. Leave it a few days before you take it anywhere in the car. Don't feed it before a journey. Take it for lots of short journeys, I start off by just driving my puppies round the village for about 5 minutes, then give a nice treat when we get home whilst the puppy is still in the car. Obviously, you will need to take your puppy to the vet for jabs. Take some nice pieces of cooked chicken with you and get the vet to give them to the puppy when he is on the vets table. You want to avoid the puppy associating car journeys with something unpleasant. When your puppy is older and able to go out,occasionally drive to the park or wherever you take it for walks, that way it will look forward to going in the car. Buy a cage for travelling, puppy will be much safer if it is confined, it also provides some protection if somebody runs into the back of you, and also, if the worst does happen and your car doors fly open, your puppy can't escape and run off. Keep a small pair of bolt croppers in your door pocket in case anything happens and you can't get to any of the cage doors to open them. You can get them from any DIY place. Have a roll of kitchen towel and a plastic bag in the car in case of poos, and a wet towel in a plastic bag for clean ups. If your puppy is travel sick, a ginger biscuit half an hour before travelling can help.
Ginger is well known for helping with nausea. Hope this is of some help.