Welcome buddy. I bought my car used from a Nissan HPC so still have some warranty remaining but, as Glasto said, the cost of the warranty is very high so I'll be looking at a different warranty when mine runs out.
Whether you think of the GT-R as stiff really depends on what you've been used to. I came from an Impreza STi and the GT-R rides better than that did so no issue there.
If you find a car to test drive then best to call the seller first, especially if it's a Nissan HPC. Some are more accommodating than others regarding test drives. Do try and find the time though as they are stunning machines
Whether you think of the GT-R as stiff really depends on what you've been used to. I came from an Impreza STi and the GT-R rides better than that did so no issue there.
If you find a car to test drive then best to call the seller first, especially if it's a Nissan HPC. Some are more accommodating than others regarding test drives. Do try and find the time though as they are stunning machines