homepage: Replace ICE subtitle with something less obscure

The "ICE systems" in the subtitle has been a source of confusion for almost everyone.

The shorthand for In-Car Entertainment is not as common as the In-Vehicle Infotainment (IVI) one, and too often people struggle to remember what the acronym stands for.

It was a good placeholder in the design proposal, let's now find something slightly more appropriate for the homepage.

Note: I didn't put too much thought here, the point here is to get the conversation started to get rid of "ICE". :D