roll hoops

As title suggests, my 97 z3 didn't come with roll hoops or a wind deflector.. I had the top down the other night and I forgot how windy it gets in the cabin when going 50+ mph! I searched but couldn't find a definitive answer but is it possible to fit a wind deflector without roll hoops? Is...

Help required please. I have purchased a second hand S/S XSPower roll bar for my 1998 Z3 but the diameter of the tube section that is inserted into the seat belt retraction cover is larger than the hole ? Is this standard ? it must be possible to enlarge it but will it fit into the metal base...