I wonder how far you'd get if you'd say (while laughing, or making other FAR too obvious sarcasm infused gestures) it was for a 'ignition system'
This is a very stupid idea. Don't even think about this. If you say it's an ignition system, no matter if laughing or not, every cop on this world will take you apart. That's the kind of jokes that makes you miss your plane. I've had a stupid work mate who asked when returning from Amsterdam the customs officer jokingly if there's an import tax on pot. Well, lets say he got the full treatment. Deserved him right. Stupidity is its own reward.
Korman