This could happen “relatively” easily because all car systems are different. It can be small, medium, big or large like a stadium, could come with 4 speakers or 12 speakers… All in all, we use default settings which work in most cases but sometimes not. If not: It can be too loud, distorted or low compared to other sources of the car (FM radio, CD).
If you experience volume problems with Gateway sources (USB, iPod, AUX), then you need to select the Gateway menu, then go to Settings and select Volumes menu option. If you enter that menu, you can browse between different volume options like:
The volume output will be changed as soon as you set the new volume level (no restart is needed).