I go to BCA all the time and I'd have to say at the moment you'd struggle. Anything 4x4 is very popular with the trade at the moment. Not just because of the snow, although that has had an effect, but also because of the week pound. Lots of diesel 4x4 are going to Africa at the moment and Petrols are going to the Far East. I'd especially steer clear of anything that is listed as VAT qualifying as that mean the exporter is already 17.5% ahead as they can re-claim the tax...... This will also mean that the 4x4 values could stay high even through the summer when they do traditioanlly fall a bit without the export market propping them up.
Also, trade buyers (which make up about 90% of BCA) have an advantage over the public with buyers fees in the region of 75% cheaper.
You could give it a go but the odds are well and truly stacked against you at the moment I'm afraid!! At the very least it costs nothing to just go along and see what it's like if you have the time to spare, and they serve up a mean full english breakfast!!!!