Yeah it sounds like they aren't managing the development/updates of the firmware well at all. In some sense, you imagine they should just be free. On the other hand, I understand that they end up bricking the units that they test on and require purchasing of new ones constantly. I just think the method of requesting the funds needs to be worked on. They come across as shady instead.
They should do like "crowd funding" for the development of new firmware and then release it free upon release. This way, they are being funded by individuals that want some enhancements, but in the end, it makes their product better overall which will end up in future head units that they sell. It's a win win for them and the end users that want additional features.
If you are a customer that is satisfied where it currently stands, then yeah, you don't need to fund any development for future enhancements. On the other end to that, if there requires "fixing" to the software, it should be a free release always.