The cloverleaf was adopted as the company logo simply because he is madly in love the automotive marque Alfa Romeo. The basic 4 leaf green clover has been on all business card and formal business atire since 2011 and remains an integral part of the company image.
The leaves of a clover are said to stand for faith, hope and love.
The significance of the cloverleaf can be read and learnt in this very useful article.
Aritcle and image source : Petrolicious