Single din only, unless you want to cut a massive hole in your dashThe FLAC issue isn't a problem, there are plenty of good file formats, and storage is cheap. The Android may be a deal breaker for you.
Are you stuck with a single din head unit? There are some great double dins with strong enough DSPs so that you don't have to buy the AF crossovers. You can run active with many Kenwood and Pioneer head double dins, have Android Auto, and FLAC. The DSP is a tad limited, but it'll do everything the AF crossovers do and more.
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