Basically fitting a rear strut brace to my T25 spec suspensioned WRX and as the top mount bolts have to be removed I'm worried it could effect geometry..!

Will struts stay in position with weight on the car and would it be a good idea to mark out before undoing nuts..?

Or is there no chance of movement with nuts off..?

 

removed the strut brace on my p1 and nothing mover also seen Matt at roger clark motersport re-fitting one after sorting out some ones geometry it just stops movement not holds the car together

 

IMHO:
You will be safe and sound.