Has anyone got an aftermarket DVB tuner in their car?

I'm looking at buying one of these but I'm not sure on how good the reception will be.
http://cgi.ebay.co.uk/630-DVB-T-IN-C...QQcmdZViewItem

I have an analogue tuner in my car which uses 4 antennas so I'm worried about this one using a crappie little antenna like the one that comes with it.

Does anyone know of any different DVB tuners that don't break the bank?