I have a 2004 Td4 HSE Freelander with a dead stereo. Its the Becker unit; although the radio works and it will play a CD the screen has gone so tuning it to a station (or doing anything else really) is virtually impossible.

The Becker unit is a single-DIN size, but there's a recessed tray underneath it which is itself DIN-sized, so I can remove that and fit a double-DIN unit. I've chosen one (Alpine CDE-W235BT) and those awfully nice people at Halfords will fit it for me. The problem is finding an ISO-to-ISO lead with the appropriate magic box to enable the steering wheel controls to work - they couldn't find one on their system. I'm a numpty with these things, I know how to press the buttons but working my way through the three platefulls of spaghetti that connects it all up is not my forte. Can anybody point me in the direction of the lead I need?

Can't help with the wiring for your steering wheel buttons but I had to replace both front speakers and tweeters in my newly bought 2002 FL1. Only one tweeter was half working. At first I thought the head unit was faulty but once the speakers were replaced all is now well so it seems Landy speakers can be a bit suspect.

I found a company called 'In Car Emporium' on eBay (http://stores.ebay.co.uk/In-Car-Emporium-Ltd?_trksid=p2047675.l2563) selling the stereo I wanted as a package with everything needed to install, and offering the lead to enable the steering wheel controls as an extra. I rang them and yes, they do the required lead at a cost of £26.95, but they told me that as my car has the Harmon Kardon amp installed, this stereo wouldn't work with it and they didn't have anything else that would. Bummer.

OK, I can't be the first owner with a factory-installed amp who wants to replace the head unit in the dash. Can anybody recommend a head unit that will work with the in-built amp? Preferably one with bluetooth capability so I can get handsfree phone as well?

Why do you want to continue to use the in built amp? I can't see why you can't use a head unit with a steering wheel adaptor as long as you find one that has the adaptor and ditch the amp.

I know how to work the stereo - I don't know how it all fits together. But my assumption is that all nine speaker connections must be to the amp, not the head unit. If that is so, then the re-wiring required to by-pass the amp is not something I'd want to undertake.

I believe that you can use the factory amp with a replacement HU. The amp simply takes audio signals from the Becker and amplifies them before sending the signal on to the speakers. It also feeds low frequency sounds to the boot mounted subwoofer.
You will need to do some wiring changes, but it's not impossible. If you can't do it yourself, an auto electrician should be able to complete the task for you. The steering wheel controls will need an adapter though, as I believe it's a digital signal used on the Becker unit.

I'm not familiar with Freelander wiring, but generally there's one problem with "ordinary" head units and that's one of output level. They will usually have the power amplifier, which drives the speakers built into the head unit with just one or maybe two pairs of output terminals (right and left). This is not usually enough to drive nine or ten loudspeakers, and it's certain;y too much to feed to the input of a big separate power amplifier which will result in distortion and the inability to set a comfortable level. Some head units have a facility to switch out their internal power amplifier but most don't.
You can use an ordinary head unit with a level adjustment device between the HU and the amplifier.

http://www.ebay.co.uk/itm/111393023065?_trksid=p2060353.m1438.l2649&ssPageName=STRK:MEBIDX:IT

You'll need to pick up the accessory wire on the head unit to switch the amplifier on or off and yes, you'll need an adapter to be able to use the steering column controls, which I believe are in fact analogue if it's anything like my 2004 Disco 2. But yes it can be done.

I think that if I were in your position I'd ignore the obvious temptations of Halfords and go to a car audio dealer - they'll solve it in no time.

Boguing, that's exactly what I'm going to do! A friend of mine had his car rear-ended by a cement lorry a couple of weeks ago and as a result its scheduled to be converted into some fridge freezers. Before the insurance company towed it away he had the foresight to remove the rather nice aftermarket radio/cd player/bluetooth handsfree/navigation unit with touchscreen and his new toy that was delivered today has it all built-in, so I get this one-year-old Kenwood unit for zip, nada, the big zero; which is nearly £900 less than it cost. Good, eh?

I rang Huets, who seem to be the most respected car audio supplier in Brighton and they've quoted me to install it - they seem to know what they're talking about in terms of what's required to fit it in this particular vehicle so I'll leave it to them. It's not a cheap job - they reckon £300 given the various adaptors and couplings required, but when you consider I've got the unit free it'll all work out in the end.

So thats all right then.