Chris,

Always start with the least aggressive product available as it is good practice in every detailing process.

A picture would help but your first course of action should be saturate the area with a dedicated leather cleaner (spray or gel will do) and allow it so sit for a few minutes. Depending on how thick the adhesive is, you should be able to remove a large percentage of the residue with a plastic razor blade or another smooth surface safe edge. You could also substitute the leather cleaner for a safe all purpose cleaner. If it were me, the first product I would introduce to the area would be deep down by topoftheline. Leather Vinyl Cleaner Due to price and overall effectiveness with issues of your nature. In my experience it is the most effective interior cleaner for the money, and also has a nice clean smell.

Or you could go straight to Leather Masters Strong cleaner. Which might not be a bad idea, because if anything is going to remove it by way of liquid produce, this would be it.
Leather Strong Cleaner
and a brush like this.
Leather & Vinyl Scrub Brush

If it were crazy glue you would most likely have to work your way all the way up to straight acetone. If the glue is a cyanoacrylics the solvent would be acetone.

There's a good chance you can remove it without taking enough die with it to be noticeable. Whatever you attempt, try out an inconspicuous area first to avoid making the problem worse.

Hi, I'm a detailer from Singapore, and I'm certainly not trying to promote my services here, unless you own a lamborghini in my country and wanna look for me.

For such sticker marks, on most surface, cooking oil, olive oil or just about anything oily should get it off. I highly recommend olive oil. Just dabble some on and rub, it should come off easily. Blot off with tissue, follow up on leather cleaning and conditioning if you want to. The same method I used for sticky wax, and thats just about the gooiest and stickiest thing you'll find on this planet. Works everytime, on almost all smooth surface including human skin. This, I learn from experience.

And please don't just take my word for it, kindly try it out on other leathers, an old car's leather. If you think my advice is total bullcrap that should be ignored, I'm fine with it. I don't want to be held responsible for ruining the leather of a 300k car.

Good luck!

Wow, a very interesting thread here.................

Yes. Thanks for the suggestions.

__________________
04 G, Pearl Yellow, Clear Engine Bonnet, eGear (sold)

I will answer this question for Holden since it looks like he disappeared from this thread, similar to how he has disappeared from any of my communication.

He is not legal to work in the states. How do I know this? Because he worked on my car and when I asked for a receipt, he balked. 2 weeks ago he sent my an email confirming he would not be giving me a receipt because the IRS may not look on his work in the US kindly. I then asked him why he would contact me in the first place if he wasn't legal to work here and he never replied.

The worst part is that he damaged some window trim on my car after doing work that I was not completely satisfied with. I have sent him the bill and he has not replied since. I could go on and on...

So much for the "professional" moniker. If no check is forthcoming to fix this screw-up I suggest you place a call to the IRS.

Well, Holden called me last week regarding my interest for a quote to detail my car, but quite frankly the quote he gave me, considering he never set his eyes on the paint in question was at best dubious.
Make a long story short, I thanked him but declined his services... I have called around different detailers (5 in total just to see what sort of numbers they had in mind, and it's safe to say that Holden's numbers were right over the top of the most expensive quotes I got... most of them also said that it was hard to give a quote without actually looking at the paint first, which to me is the right answer.
Of special interest is the fact that Wayne,owner of Avenue Collision and a detailer par excellence told me that a full detail job done to perfection which may also include a light water sanding with ultra fine paper/or fine rubbing compound followed with a wax/polish and sealers would be around the $400 mark... whereas Holden's quote was close to a $1000.00 after all is said and done!
Just to clarify,Avenue Collision does a lot of work on Porsche,Benz,& Ferrari; not sure if they ever worked on any Lambo's and in many automotive circles are one of the highest rated repair facilities in Toronto.

Key03, I am not looking to hurt anyone, I just want to be compensated for the damage that he caused.

Rugger, $1000 was a drop in the bucket compared to what I was charged. I sure wish I had done some diligence before I went ahead with the work. I just got caught up in the excitement of getting the work done.

"Key03, I am not looking to hurt anyone, I just want to be compensated for the damage that he caused."
That's pretty unprofessional of Holden, If he did screw up a part on your ride the least he could do was cover the replacement/labour costs involved.
That's just wrong!!!!
$1000 a drop in a bucket? Way over the top for me to pay that sort of dough for a polish,but that's just me!

To be fair, the service on mine was the restoration he advertises as "Perfection", which was much more than a polish.