Recently preformed and oil change in which the rear body diffusers were removed for better access. I have also encounter a fewdecent pot holes at a fair speed. My car now seems to be a lil less solid and at higher speeds 80+ the body diffuser to my knowledge are all on in the right places. My question is do you think the alignment is off and causing the problem but i dont suffer from any real drift in either direction...or is something not right with the diffusers?

or could the roads and wind just be the factor? i have only noticed this after the oil change any one else encounter a similar problem or have any advice?