Off the back of a lorry
Definition 1 of 1
Pro Tip 1/3Cultural Interpretation
In the UK, this phrase implies suspicion about how something was acquired, suggesting it may be stolen or illegitimate. 
Are those designer bags genuine, or did they come off the back of a lorry?
Pro Tip 2/3Slang Usage
It's a slang expression, so it's best used in casual conversations rather than formal contexts. 
He's got the latest phone already; must've got it off the back of a lorry!
Pro Tip 3/3Humorous Tone
The phrase is often used humorously to tease friends about newly acquired items playfully. 
Nice watch! Did you get that off the back of a lorry, too?