Dead fish/fish pieces in a hubcap...or fish chucks down the fresh-air cowl at the back of the hood...depending on the model of the car, it might cost just a bit to remove the pieces...they have to be big enough that they don't wash out the holes...

Buck-rub in the vents works just as well and it's not a scent that most city-folks would recognize right away...

__________________

M. G. Burg
'10 - Dakota SXT - Daily Ride / ≈ 172.5K
.'76 - 450SLC - 107.024.12 / < .89.20 K
..'77 - 280E - 123.033.12 / > 128.20 K
...'67 - El Camino - 283ci / > 207.00 K
....'75 - Yamaha - 650XS / < 21.00 K
.....'87 - G20 Sportvan / > 206.00 K
......'85 - 4WINNS 160 I.O. / 140hp
.......'74 - Honda CT70 / Real 125
.
“I didn’t really say everything I said.”
. . . . . . . . . . . . . . . . . . ~ Yogi Berra ~