I used to work for a Self Storage company in Plaistow. We had people store cars all the time. In terms of the lip, it was in excess of 1.5 feet in some places.
We had 2 HUGE boards (3x12 roughly) that we used as ramps to bring the cars in and out when needed.
Also, shop around and find some good rates. Don't be afraid to negotiate a price with anyone that isn't a national chain. At my facility we did not have a published pricing list. It changed with every new customer. Basically we tried to get everything we could out of someone. It was like used car sales. Start high and make them think they're getting a great deal. If they don't question it, even better.
