Since you prefer a diesel car and have performance as a priority, the BMW 3 Series in its 320Ld guise fits the job perfectly. It is excellent to drive, has a punchy but refined engine and surprisingly strong efficiency. The boot is also generous, although not as much as an SUV, but at this price, the practicality is very good. The only things to consider would be the low ground clearance. The driving dynamics, comfort and features are excellent, and it has fantastic touring capabilities.