Open Question: How do you start your own car sales business?

My husband is looking to start his own car sales business. He has experience in cars as well as some mechanical experience. It has been a long lasting dream of his to sell cars and he would love to start up his own business. My question is: What is the best way to get into this busniess? What will he need? Would it be better to start of small, selling at home or to rent a unit to sell from? He wants to deal with cars between the price of £1000 and £5000 (selling price - not buying price). How much money do you think is required to start up? Any guidance, advice or experience would be very much appreciated. Thank You.