Didn’t know that Nissan boy, I’d say you hit the nail on the head.
second hand head units are cheap enough I got a pioneer with dab for 20 squids on the site that sounds like spok with a lisp. Another 25 for a roof mounted amplified aerial and I got better dab signal than my bmw.
i would recommend better speakers for the shelf the standard are even weaker than the door ones, jvc standard replacement ones are a huge improvement and can be found for as little as 15 quid new on fleabay.