So I sent a pm to Marcel Offermans on 17th August 2018 about Any chance of getting window templates for the gt3 mod please. With no reply to date. Now that is ok, I guess as people have lives to live, so now I will ask everyone at studio 397 if someone would like to reply to the request.
It is strange that you have been asking this seemingly very simple question with no replies yet a question about the progress of the dirt maps in the July Roadmap thread gets a reply in an hour.
They surely have. I think everyone should be much more patient with them. You should know that in recent times their first priority was to release content and keep it playable - nothing more or less. As soon as there is some time for visual things, they will for sure spend it. Or maybe they already have but they had no time to complete QA yet, who knows!?
I am a patient person but this has been requested from October 2017 that is when I {we} ask for the window templates. Ever time since then I get someone comment about how childish or impatient I am for requesting these templates. If I could get to the mas files I would make them but we can't get into them. So I guess this won't happen damn shame for a paid content.
Do what I did and make your own. Open and extract the teams Mas. There are examples in there. Only the Callaway isn't but you can search it out to make it yourself. Even the GTE cars although we did get them they are rubbish but at least you get the wire as a base to start from. A year! Wow that went fast!
There may be a good reason why they haven't been released but surely there is no reason there has been no response to the question? "Yes", there's a chance they'll become available or "No", there's no chance. It should be easy to answer a simple question.