With a test drive, I always make it clear that I want a decent time with the car – certainly at least a few hours and ideally longer. If they pull a face or say that they usually just give people an hour (or less) I say that I will be living with the car for at least 3 years and cannot possibly make a decision of that importance in less time. Usually that works.
All new cars can impress in the first hour, but it’s only when you’ve had it for much longer that you start to see the full picture and any possible drawbacks start to appear. There have been countless examples on this forum over the years of people who ordered a car after a very short test drive and then realised when they took delivery of the car that it wasn’t right for them.
How dealers handle test drive requests is often a good measure of how helpful they are going to be throughout the order process and how confident they are in the cars that they are selling. Before we ordered our current BMW X1 we had a 3 hour test drive and loved it but told the dealer that we didn’t think that the standard seats were very comfortable and we wondered if we should opt for sport seats. Rather than just suggest that we sat in another one with sport seats, the dealer gave us a brand new X1 M-Sport (with sport seats) and said “have the car for a full day and go as far as you like to make sure that you are certain”. We ordered with them and they were brilliant throughout the whole process. We got the car in 3 months when others on this forum ordering the same car at the time were waiting 5-7 months.