all depends, if its a nice clean looking car you should be fine, keep wheels inside the guards you should be right, been pulled over twice in mine(is a ghetto/POS looking faded red ke70) never been asked to pop the bonnet, nor defected(fined for rear tyres), talk politely
at the end of the day everywhere is different, if you drive like a F wit expect to get pulled over(there is a time and place for everything), ae71 and ae86 4age is from the same family, so unless the cop has half a brain(you get 4age engine number on rego papers) they wont know, ke70 on the other hand(4k) its not the same engine family, and realisticly if the cop was a dick, its the same fine and point loss(7 points i may be wrong) as driving turbo/suercharged/v8