When I bought my Mk1 MX5, the first thing I did was install a new head unit and the best speakers I could get. When sat in the garage it sounds great, but with the hood down on the move the sound is obviously not great. I therefore have done what the guy above did and I use bluetooth ear buds connected to my phone. The sound is great and as I have a lot of music and a link to the radio on my phone, I have no downsides. I can also use the phone if it rings. The only downside is you are cut off somewhat from the world outside. I am sure there is a safety issue here, as you become lost in your own world. However the sound is the best you will get.