I bought second hand some nearly new Protech shocks some two years or so ago. Although the car they are fitted to has not moved since, I just haven't finished things yet(!), one of the shocks had a leak. I phoned Protech who told me to send in the pair as they might be covered under warranty. Even though I admitted I had not bought them new.
Shocks duly sent off, I phoned a couple of days later simply to ensure they had arrived. The chap I spoke to said they had them and would be repairing the problem and there was no charge. The next day they arrived with me.
What can I say? Brilliant service.