Can I install Android or custom Linux apps such as Google maps etc?

The operating system that Odyssey3D is running on is Linux. Therefore, no Android apps can be installed on it.
Furthermore, Odyssey3D was developed with performance and fast startup time as first-class citizens.Thus, a lot
of Linux functionality has been stripped down and access for custom Linux apps cannot be given.

Can Odyssey3D operate with the high temperature of the car interior?

Yes. The Odyssey3D hardware is comprised of electronics used in automotive or outdoor robotic projects.
Furthermore, ABS filament was used for the 3D printed parts which is very resistant in high temperature and usually used in automotive parts.
Finally, Odyssey3D has been deployed and used for over a year and during the hot Greek summer without any problems.