Inclined to agree with Tunnie here..
I browse the forum via a slow remote control link...
Some of the large signature images really degrade the browsing experience, as do any animated ones....its eqivalent of watching a video over an old modem!
We have the gallery for car pics!
I think small ie 1 inch x 3 inch non animated pics should be the absolute limit.
Some pictures are that large they need scroll bars!
No offence meant to anybody, they are just my feelings.
I have privately asked 2 people to amend scrolling pictures in the past, and both have been very amicable over it.
I know my situation is unusual, so don't expect any/every one to change for my benefit.
Maybe sig's should be text only? leaving avatar's for a picture or animated gif?
Think you put it a bit more politley than me!

But exactly... have links in your signature to your gallary pictures.
The problem is when a big discussion kicks off, and you have the same person posting say 5 times, you have that persons car/graphic displayed 5 times....
Some of them are worse than others, yes your car looks great, and its nice to look at the pictures every so often, but every time you post it gets annoying!!
If you really want to shown off your car, make your avatar animated with its pictures... with a link in the signature.