Could try a tip someone gave me, sit in the centre of the back seat. put your arms up the joint in the inner liner to feel the metal bars, then push the bars forward. I did not help mine as it was 15mm away but for small adjustment it may help. Also i assume its an electric roof,have you checked the fluid in the pump in the boot, if low wants to be topped up. Ford fluid expensive ,vw the same but cheaper (so most people say)