I recently used Formula one for an aircon regas and clean. It was easy to book online and the price was competitive. The staff at my local centre are always very friendly and helpful, clearly setting out when the car is likely to be ready for collection and phoning to confirm when it is ready. The only negative comment is that, unlike when booking for new tyres, there is no am or pm option. You are advised to phone the centre to make an appointment. The centre did not seem to know why this advice is given as it is simply a question of what other jobs are in before yours on the day, so the phone call is a waste of everyone's time. It would be helpful to change this message on the website for aircon bookings.