Ideally, you'll want something classic. Is there a particular aspect that you're looking to highlight? Something like a Triumph Herald or a Ford Anglia 105E would be perfect for the mechanical side of things - although neither are cheap now. Perhaps you could look at Series Land Rover? The older the car is, the easier it will be to see how it works - but the more expensive it will be. Have a look on eBay for a 'spares or repair' car near you - if you've got a trailer or a way of moving it, that's going to make it a bit easier. When it comes to dismantling the vehicle, then there are plenty of things to be aware of. End of life vehicles are normally handled by authorised treatment facilities that have the proper facilities to dispose of hazardous waste such as oil, brake fluid and batteries. You'll need to look at what facilities are available to you locally. Be mindful of the paperwork - keep the DVLA informed if the car is off the road or if it's been scrapped. If you don't, you could be fined up to £1000. Finally, be courteous to your neighbours. While there's no law on working on a car at home, angle grinding at midnight is unlikely to make you many friends. And if you have a pile of hazardous scrap metal dumped on your drive, then expect problems - store the car and the parts you remove safely.