This was requested by mauelmusical14, I hope this suits what you were hoping for.

She didn't want to hurt him and she'd much rather be doing this in person than by letter. Unfortunately though, she simply didn't have enough time to do so, such is the life of a spy in the field.

If she were to tell him in person, she'd want more time than a tireful of minutes to do so. Not to mention there was always the chance of not returning from a mission.

Where as a letter, this letter, could be written on the way to her next mission and he could still receive it even if her mission went sour.

Her engine felt heavy as she wrote the letter. She had genuinely enjoyed the time spent with him, and he really deserved better than just a letter.

She knew he would come to understand why; he might be disappointed and sad for a bit, but he had a good kind engine, with an innocence she'd hate to see snuffed out.

She'd make sure the letter would make it to Radiator Springs though.

It wouldn't be fair to him to disappear without a word at all and that, more than any other reason was why she was writing it in the first place.

Hopefully it wouldn't dull Mater's light for too long, the world could use more of it.

oOoOoOo

Dear Mater,

With a heavy engine, I write this letter. I'm sad to say, our time together has come to an end. As much as I would like to stay; I can't. Life as a spy; particularly a field agent as I have become from our mission together, means that I'm always on the move into multiple dangerous situations and one day I mightn't make it back.

You've seen from first hand experience how dangerous spy work can be. How easily loved ones, whether they are family or friends can be used against you, like McQueen was.

Finn's already lost one partner in the field. I can't let Finn be alone in the field, and Siddeley can only go so far; being a plane leaves him unable to be adequate back up as he can not fit in the same places as a car can.

You are one of the kindest and sweetest trucks I've ever met, but your friends and family need you more than I. It would be incredibly selfish of me to keep you from them. No matter what happens Mater, I shall always consider and call you a friend, for you shall always truly be a friend.

I hate that I'm doing this by letter as you deserve to hear this in vehicle. Alas my time has left me unable to do so.

You would never leave Radiator Springs for an extreme period of time because it's your home. While, I am not prepared to leave my job.

Currently, I am learning more of the nuances of being a field agent. It leaves me with little time to visit or be in any kind of contact, less it otherwise risk the mission or put the lives of you and your friends in danger. I don't want to put them or you in danger; I wouldn't be able to live with myself if anything happened to you or them.

To clearly put it instead of dancing around the issue; Mater I am breaking off any relations we have for your own safety. I know it hurts, and I really don't want to, but you will be safer this way. I hope you can forgive me, you are such a wonderful vehicle; I don't want you to lose your innocence and light that you have. It can happened in such occupations as spying, that vehicles lose hope and happiness. I don't want that for you.

You don't have to forget me, I won't forget you and neither will Finn or Siddeley. This isn't a farewell though, just a see you later. Once everything settles again, we'll visit, but it could be years before then and if a mission were to go sour, we mightn't make it. I just don't want to keep you waiting on false hope.

But Mater, I had a wonderful time with you, I wish you the best of luck.

Holley

oOoOoOo

At first Mater had been excited to get a letter from Holley, but by the end of it he was sure what to think. He did know that spy work was dangerous, he had lived it during the World Grand Prix. He had helped expose Axelrod as a fraud and that had almost ended with Holley, Finn, Lightning and him dying, so he understood Holley's point.

But dad gum, she was right it did hurt.

Nobody needed to know about the letter much less Luigi and Guido, who had been so disbelieving of when he first told them all of Holley.

Course, that all came out of a misunderstanding, but it worked out for the best at the time and Holley really did like him.

Hopefully she and Finn would stay safe, he wouldn't want anything to happen to them. It would be a case of they'll get in contact with him, not the other way around because he could get them hurt if he tried to contact them.

He'd leave them to it because Holley was right. He'd never want to leave Radiator Springs, going to Lightning's races was one thing, but what Holley was talking about was something completely different. One thing was at McQueen's races everyone was pretty much there anyway and they'd stop by town every chance they got.

Holley was talking about not even visiting for years, and then the constant danger they'd be going into. It wouldn't give him much time to make his art either. He was content with his life, he didn't need the excitement of spy life, he had tractor tipping to spice things up and that he could do with his best buddy.

He would miss Holley herself, but he would have missed her being away anyway. Maybe one day they'd get a chance to see each other again, but until then, he'd keep on doing what he always did, being a tow truck.

So, without the request, this likely wouldn't have been written for the fact I'm not overly fond of Cars 2. I may make vague references to it, but I found the whole spy thing a bit over the top and thought that part of the movie would have made a better Mater's Tall Tale. I can't bring myself to ignore it completely because I like the idea of the World Grand Prix.