Diesel fuel smell in VW Diesel

2005 VW diesel, runs fine, no odor until local garage replaced fuel filter, fessed up to “cracking” fuel line valve, replaced it but have had quick puff of fuel smell often when starting up from stoplight or starting up cold or after being parked for hour or so. Disappears instantly & doesn’t always happen. When warm weather began could smell fuel odor while driving & coming in passenger-side window when it was open. Local garage can’t find cause, power-washed noise-deadening blanket & engine compartment. VW garage couldn’t locate cause but replaced parts of fuel lines for $200+. MPG is down from 50+ into 40s. No drips or stains under car when parked. Any ideas? Please? HAve called VW of America but can’t get past ‘customer advocate.’

You said no drips or stains under car when parked. Have you tried letting the car run for 20 minutes or so in one spot to check for drips? I’d give that a shot.