But we are precisely talking about age-related loss of accommodation here, a.k.a presbyopia. I take it you're too young to have first hand experience of it?
If you are not able to focus on close objects, then you basically have three options:
1. Move the object further away, so you can focus on it (impractical in this case)
2. Wear glasses - which would have to be bifocal or varifocal to avoid interfering with your ability to see the road, or
3. Accept that the screen will be slightly out of focus, but make other accommodations to maximise readability, such as larger text and high contrast text, so that you can easily read the text despite the fact that it's slightly out-of-focus.
For most people, option 3 is preferable - unless the condition is severe enough to make option 2 unavoidable, I guess.
EDIT: Actually, for completeness, there's a 4th option, also largely impractical in this case: ensure that you're in a bright enough environment that your pupils are constricted, as this aids in focusing.