The stated kerb weight of a vehicle often allows for a driver and a tank of fuel. Therefore the actual weight of the car on your trailer may be quite a bit less than the stated kerb weight.
Recovery winches differ from smaller 4x4 winches and boat winches. A recovery winch is far larger with a higher pull rating, thicker cable and stronger hook. In the interests of safety, only use a recovery winch to recovery a car
The key to transporting a vehicle on a trailer is to have the correct equipment. The combined weight of a Transporter Trailer and the car it is carrying is beyond the maximum permissible towing capacity of most normal passenger cars.
Unless the car being transported is very light (i.e. a track car) a Large 4x4 or commercial vehicle will be necessary to give the required power and mass to keep the trailer stable.
A suitable trailer will also be required, these can be hired at a daily rate or purchased but keep in mind that a suitable trailer in good repair may well cost upwards of £1000!
When loading the trailer try to keep the weight as far forward on the trailer as possible. For example, always load a vehicle with the engine at the front as this is very heavy, put rear engined sports cars on backwards.
The towbar on the tow vehicle will have a maximum loading weight (typically around 100kg, but refer to your towbar manufacturer for precise specifications). Make use of all the towbar nose weight that you can as this is transferring weight away from the trailer and onto the rear axle of the towbar.
This is why it is important to have a heavy duty 4x4 as a tow vehicle as standard passenger cars do not like the back axle loaded too heavily.
Attach the car to the trailer at each wheel using heavy duty ratchet straps. DO NOT be tempted to purchase cheap lightweight straps as these will simply break if put under to much load. Remember, you are strapping down a heavy car and you do not want it to become detached from the trailer under ANY circumstances.
The cost of a large 4x4, the expense of hiring or buying a trailer and heavy duty straps and the stress of trying to keep the entire rig steady and safe at motorway speeds means that for most people it works out far cheaper and less stressful simply to pick up the phone and hire a professional car transport or breakdown company.