Yes, but I think any level of Avis Preferred gets you that service where you're pre-assigned a car and just show your licence on exiting the rental depot (though in practice it only seems to work - for me anyway - with any degree of regularity in the US)

Answering my own question about the higher tiers of preferred in the Avis UK scheme the info is here - http://www.avis.co.uk/loyalty .. upgrades is really the only concrete benefit it seems - and I guess could be decent ... However given that it's only UK rentals and a fairly small list of other countries that count I don't think it's that easy to achieve for me anyway.