Nice work Peter.... I assume that now you've got this clean and sorted that there are a range of speakers you can now fairly easily insert as you gradually upgrade? Maybe even a power amp back there?
The system is now nicely balanced.
I can listen to music or Radio 5 Sports Extra when I want or just enjoy the 4 woofers mounted under the rear of the car, as Jay's advises. The two are not exactly compatible... both have their place.
The next "logical" upgrade would be a full power amplifier to drive better quaity speakers and a sub-woofer. To do the job properly is £2000 for hardware and a lot of labour...in an open car I do not think it would be worth the money.
