Two things that may help you with the auction lag...
1--- Stay in the main auction window and use "x" to refresh. It has that page preloaded pretty much all the time as it's the priority to keep up to date, so it's much faster coming back to it. (unless the server is on an off day, then all bets are off. )
You'll get the newsflash on the bottom saying that you got out bid, don't panic. Unless you're in the busiest time of day, hit the "X" button and start scrolling, you will scroll to the car quick enough. You don't even need to pay much attention to the mail really, as you're always near the top of the window and after you refresh any cars you're bidding on will be near to the top anyway. Because it's the main loaded list, when you come out of bids, the screen refreshes much more quickly than if you are in your own bid list.
2--- IF you end up in your own bid list after pressing the "A" button for a re-bid and you come out to the My Bids page, 9 times out of 10 it's blank and the circle is spinning and spinning as it searches endlessly for whatever the heck it was you were doing...
Then do the following...: Left trigger to mail, which will take you to an out bid notice. Don't wait for it to load, and it doesn't matter which one. Just immediately click "A" to open it.
This will bring you right back to your My Bids page, which will now be loaded and current without the waiting. For whatever reason, your bid list is kept cached somewhere, up to date, but it isn't tied to the auctions or the auction listing. It is tied to your mail, however...
I've waited 30-60 seconds for the My Bids window to find and display everything I have going, while it takes maybe 5-10 seconds to go left trigger then A button to My Bids, if that. I've yet to have the screen update faster than I can get to mail and get back again.
I prefer to stay in the main window if I can, and to do that just don't answer the mail... If I have to, as soon as bids are caught up go to Search, leave it at any/all and back to the main window ASAP. Anytime you're not in the main window, you're missing potential steals.
I also ( try to ) keep my bidding to 2-4 cars at a time, and pull credits as I go when there's a lull. I'm just looking for cheap dates and for high class rated cars I don't have Affinity with, as many times I can get a fully decked car for less than it would cost to build it. Then I go after whatever event I can use it in to build the Affinity or strip it, sell what I can and redo the car after the way I to do it and after I have the Affinity to do it for 0$ parts. Note that if the person you got it from didn't pay for the parts, you may get 0$ for them. Exceptions are body kits and wheels, unless 0$ option from the factory.
I've had some really good steals, like pulling a fully optioned V8 Super Car for 38k... Sure you get "a" free one, but this was a nice piece to paint and make my own livery for.