The short answer is that it's impossible to provide a definitive answer.
The shelf life is highly dependent on the temperature. Being kept in such a warm environment should have shortened the shelf life dramatically. Whether that means that it's unsafe is a difficult question to answer. And even if it's safe, it might not be pleasant to eat.
It's entirely possible that it's safe to eat. MREs, which are similarly packaged, have been shown to be safe to eat after decades. https://beprepared.com/blog/3496/mre-meal-ready-to-eat-shelf-life/ However, that doesn't mean that all old MREs are safe to eat. It also doesn't guarantee that old fish is safe to eat. It just shows that it's plausible that it might be safe.
A car is a rough environment for packaged food. There's a chance that one or more packages were compromised by repeated flexing, abrasion, or high internal pressure from thermal expansion. The result would be unsafe food. I recommend throwing it out.