You haven’t given me much to go on here, Rebecca. There are plenty of warning lights on a dashboard these days, and even a 2005 model will have a variety of lights that illuminate to tell you something’s not right.

There are also a host of reasons for the car not starting, so it’s all a bit hit and miss at this stage. To gain a better idea of what’s happening, you could grab the owner’s manual and try to identify what symbol has lit up and which of the car’s systems it represents. From there, you can start to narrow down the causes, but an electronic scan of the car at a workshop sounds like a pretty wise investment. The warning light might even be a by-product of the engine’s refusal to start, and may go out when the engine is finally running.

I assume it won’t unlock using the remote, but guessing it probably would with the key. It could be an issue with the key, perhaps replace the battery, or with the sensor on the boot release.

Yes, parts are available, and will continue to be available for the foreseeable future.