Your two biggest concerns are hydraulic system issues mainly leaks and weather intrusion fancy name for a leaking roof.
Opel tigra roof problems.
Check for any dampness in the footwells and carpets.
The retractable hardtop roof is put in motion by hydraulic actuators powered by a hydraulic pump.
Hallo ich habe ein problem mit der hydraulikpumpe die das dach und den kofferraum öffnet und schließt.
Ich kann die folgenden ursachen ausschließen.
You need to pump the hydraulics manually to do this first sit on boot and press boot button for a few seconds without allowing the boot to open.
On the 2004 2009 vauxhall tigra you have the retractable roof which goes into the boot.
Partially allow boot to open manually push boot all the way open and closed a dozen or so times to manually pump hydraulics.
The things to check regarding the roof are.
The roof on my vauxhall tigra will not click into place the parcel shelf just keeps clicking and it wont finish its cycle.
Holden tigra roof wont open windows go down boot.
Try lubricating all accessable moving parts ie the hinge parts with something like wd40 might just be a bit dry and need a bit of maintenance now and then apr 09 2014 vauxhall astra cars trucks 1 answer.
It is not uncommon to have problems with the roof or the boot.