Personally i used a 32mm rubber grommet i had in my van (i'm an electrician), as the 32mm ones are fairly hefty ad plenty of room for the loom and gauge hoses...however there's no tail on these, didn't see it as much of an issue as the hole was fairly high behind the blower motor so no chance of water getting in. Have a look at this site....they even offer free samples http://www.plastic-parts.co.uk/mss/m...S-6TMAT5-04034