Trouble fitting RaceLand windbreaker

[Chickateee]

Bought one from ebay. All looked fine. Removed the little plugs next to where the tonneau pops on. Was just about to pat myself on the back, only to find the screws don't thread on properly so it's too loose and just falls off at the drop of a hat. What can I do? Bigger screws or does this piece just not work on a MK1 Eunos Vspec? What are my options? ANy help greatfully received. Link to a similar windbreaker below.

http://www.ebay.co.uk/itm/mazda-mx5-wind-deflector...

Thanks!