I would fit a small graphic eq in the small dash box. I am not 100% certain about the radio/centre console price but it was really the only easy place to fit a radio/cassette unit.

I have had a couple of Micro vans but not the Hi-jet and most can fit a standard DIN unit into, onto, or under the dashboard area.

You could always ask at a decent Car Hi-Fi installers as they will probably give you some better idea of what can be persuaded into the available space. There is a security box which might just fit on top of the dash and allow all the wiring to pass down to the doors etc.

I was looking at the optional parcel metal parcel shelf at the rear and then panelling it with plywood and carpet. Into the front face some 6" component speakers and a modest power fourway amp. The front doors are quite thin so you'd need to fit spacer rings if you are after serious door speakers although two way 100mm component speakers will probably fit without causing problems getting in and out.

I ran a 4 x 25w system with 9 band graphic in my Rascal which coupled with 200mm 3 way speakers in the rear quater panels was seriously loud in such a small space. Like driving around inside full ear headphones!

Unfortunately the current Daihatsu Extol is too uncomfortable for me to drive as there is not enough leg room in the cab for those of us over 5'5" tall so I will have to look elsewhere for a new home for a LOUD install. But the Extol is a very secure and confident drive and will suit many potential buyers perfectly

Good luck with your quest.

regards

Stu