Ticking noise from engine

[Lanark]

Hi All
I was about to trade my 03 3.2S Boxster at my local Porsche Indy Garage for something newer. All was going well until the salesman took a look at my car and heard a light ticking noise.

So some info

When it’s cold it’s inaudible
When it warms up you can hear it but it’s not loud, it’s quiet.
When you put your head down at the right side of the car you can’t hear it, but you can at the left side of the car(looking forwards)
I have had the car 5 years and 20,000 miles and it has always made that noise
No difference when you put the clutch in.

Thoughts please

He suggested the beginning of IMS failure. I am wondering if it was an excuse to get out the deal as he offered me £500 more than I was hoping for and £1000 more than I was expecting