Well, I used to have a non transflective in a tinted Saturn Vue, and with sunglasses on, it looked like a Black BLANK screen when it was even remotely sunny. This was a liliput EBY701. On my 2nd carpc, I didn't make the same mistake and went with the optical transflective from mo-so-co.com. This was by FAR the most expensive part of the carpc, but the most used and the most visible. This is definitely not the part to skimp on. With the optical transflective, it still washes out a little in bright sunlight (yes my windows are tinted) but it's easily readible and 1000% better than the non transflective. Before, I'd have to pull up my sunglasses and look really close to the screen to distinguish anything.
Get a transflective if you can afford it