My IS250 SE-L has 1 year warranty remaining, i purchased it from a auto dealer who the ex-owner part-exchanged with. Do i need to do anything regarding the warranty to make it valid in my name or anything?

u shouldn't have to. the sales receipt from the dealer should be enough. i would just ring ur local lexus n register ur details with them

For any warranty claims, they will be noted by Lexus GB if yours should need any work as the Warranty is on the car and not to the owner.

The only reason you should update these details (IE: new owner details) is that you can be sent a reminder that the Warranty is due for renewal. Vehicle recalls etc. are done through DVLA. I personally would have details updated to show car was in new ownership - but thats just me.

when you say details updated, do you mean update Lexus GB? I have already given my details to my Lexus Dealer is this enough or do I need to contact Lexus GB? and if so how do I contact Lexus GB?

It's the car that is warranted, not the driver/owner. So I would say you don't need to worry too much about it at all. If you have any concerns, speak to the dealer who will advise you.

It's best to let your dealer know - that way you might start to get the Lexus Magazine....