I learned the hard way, but one tip I have learned is never buy a car new as it cost me £43,100 over 4 years.

Vaxaul Cora £9,100 new sold for £5,000 12 months later
BMW 3 Series £31,000 new sold for £20,000 12 months later
BMW 7 Series £52,000 new sold for £30,000 9 months later
Ford Mondeo £16,000 sold for £10,000 1 year later

Call me stupid but I will never do it again.