Some new cars don't have sump drain plugs (I don't think the smart car ever did)
I was told that the vacuum can often get more out than the drain plug. The only advantage with the drain plug is seeing what is stuck to the magnet, but then most manufacturers don't even bother with magnetic plugs these days.
I fancy getting a vacuum though as both my cars now have undertrays which double the time to do the job.
Just over £40 for this 6L one from Amazon:
http://www.amazon.co.uk/Pela-6000-Pu...1091894&sr=8-1
Seems to get good review too