I drive an '06 that I am in love with. I particularly like the fact that, given that it was at the beginning of the product life cycle, it has fewer farkles and fancy electrical niceties to go wrong. For example, it has a manual adjust steering column. That's a big gnarly one to repair.
Having said that, you can rely on RRS' to have pretty consistent issues (i.e. they will all have pretty much identical issues). I found that mine has cost me roughly $5k in fixes but hasn't bothered me one bit, so they are reliable in their unreliability.
Common things that'll be wrong with, or will go wrong with yours are:
1. Suspension bushings front and rear. Replace them with Polybush. It's a less compliant ride (whatever that means...I haven't noticed), but will far outlast the rubber bushings that typically last between 50k-70k miles.
2. Rotary spiral cassette coupler in the steering column. This connects your steering wheel buttons to the guts of the car. This frequently triggers 'cruise control not permitted' on the gauge cluster display and can trigger a check engine light as well if you try to fight it and use the cruise control.
3. The coolant reservoir / sensor will trigger a low coolant level warning in the gauge cluster despite being full. Granted, if you have enough coolant, that's great, but not trusting your reservoir, gauge cluster kind of sucks too.
4. Hood latch sensors. These give out causing the alarm to go off randomly.
5. Moon roof drain tubes. These can clog. When they clog, moisture gets trapped in the vehicle (duh), making it a greenhouse after it rains, and also potentially leading to faults and corrosion in the electrical system. No Bueno.
6. A/C compressor. This isn't fair to pin on Land Rover as literally any and every car has its A/C go out. Still, you can plan on fixing it over 100k.
7. Heater cores. These can clog, on the driver's side in particular (LHD), leading to baffling cold air when you'd think that that wouldn't be possible with an ICE vehicle.
8. Air suspension - valve blocks can give out and air springs can dry up and crack, leading to a sagging vehicle, but I think LR did a brilliant job with designing the EAS as it still functions even as it (or part of it) fails slowly over time with age, wear, and tear...unlike previous systems in the P38 and L322 which appear to give up the barn when a single component fails IMHO.
9. Engines and transmissions. People seem to love the 4.4l AJ-V8 used in the 06-09 RRS/LR3 and while there are a smattering of stories about transfer cases binning themselves, the engine is considered to be exceptionally solid. The 4.2SC I don't think has the same reputation for reliability though. Correct me if I'm wrong.
10. Rattles - common rattles and vibrations (not including shot bushings) include under the dash, the moonroof shade/headliner, and the center console cupholder cover (when rolled back).
Even with all these things though, an '06 (and '08 too probably) RRS is still an exceptional vehicle and value proposition given what you will pay for one (in terms of its depreciation) and the costs to fix the issues. Will you ever get your money back? No. Is it less than the cost of a new Corolla? BY FAR. Does it have Apple CarPlay? Stick your phone on the dash and use the aux port.
Okay, that's all I got
