Yes, the vents will fit. the right side has all the fittings just coin box needs cutting.
for left side, dashbaord needs to be cut with proper measurement for grill. the grill has to be supported from the inside which can be done using hot glue.
The only solution if u dont want to cut ur dashboard, is to find an old model dashboard frame. there will be no issue of fitting as it will fit directly. but remember, dont expect a high blow from all the grills because the blower in mehran is not that powerful.
Another thing is the direction settings of mehran are very poor, try adjusting it from the lever near blower, because when u do it with the round setting nobs on the side of meter it doesn't direct air properly so u feel less air coming out.
by the way i have done it on both sides. i have to use the blower on setting 2 to get adequate air.