Possible Clues:

• Diamond edging for rich decoration on vehicle
• Quadrilateral with opposite sides parallel and opposite angles equal
• Figure old motor starter is installed in right-hand vehicle
• Diamond shape, in geometry
• Certain parallelogram
• Form of quadrilateral
• Diamond old maiden dropped in shrub unfortunately
• Greek character on passenger vehicle carrying minute figure
• Diamond found in coach parked by hotel within memory
• Diamond ring hunted on motorway, all kicking off on public transport