I'm not a lawyer but I do have two of them in the family and I have stayed at a Holiday Inn Express.
If this had been in the US and assuming there was enough probable cause to pull him over for exhaust noise in the first place, then there certainly was enough probable cause to look under the car and take pictures.
I know you're argument would most likely hold sway, but I wish more PDs would have to defend these types of actions in court so they would be less likely to do this with the intent of injecting themselves into 'normal people's' lives.
This wasnt a search for illegal weapons, drugs, or kidnapped persons, it was harassment for the intent of writing a ticket (municipal revenue generation).
2011 Mustang GT M6 3.31s
Matt HONEYCUTT Tune, Lethal Off-Road X, GT500 axlebacks, J&M LCAs, UPR UCA, Whiteline LCA relocation brackets, Eibach Pro-Kit Springs, Koni STR.T shocks/struts, GT500 strut mounts, SR Strut Tower Brace
Best 1/4 E/T (05/18/14 MIR - no tune, X-pipe, or UCA): 12.920 @ 109.40 mph (2.059 60ft)