Marshall spent nine years as executive divisional manager at Hella and also worked at Lucas Aerospace and Lucas Braking, after a spell with the Royal Navy as a helicopter pilot.
She said: 'I am delighted to take up this position in order to raise the profile of small business across the industry and beyond. My principal efforts will focus on quality and accountability at all levels.'
Lawrence was previously group finance director for Lighthouse Group plc. Before that, he was senior manager at Grant Thornton.
Richard Horsman, chief executive officer of Cybit, said: 'He will play a key role in helping to steer Cybit through its continued growth and development as we focus on our clear business goal of becoming the UK's number one provider of telematics and fleet management solutions.'
Before joining Rolls Royce-Bentley in 1999, Wade worked for 12 years with Volvo, later becoming UK sales and marketing director.
A trained accountant and Fellow of the Professional Institute of Sales, Institute of Sales and Marketing Management and Royal Society of Arts, Wade succeeds Mitac's retiring joint managing directors Graham Samways and John Thompson.