Not just talking about things disappearing. In chases, especially in Drug Wars in TBoGT, if you keep looking behind you you can eventually outrun your pursuers. However if you face forward the game keeps "refreshing" their position and they immediately warp right behind you if they start to fall behind. At the 100+ levels its gets really annoying trying to drive while looking backwards because otherwise you'll get torn apart in seconds. --- ?
It's not an easy thing to program, you know, allocating resources to things you can't see. Especially this late in the consoles' life cycles, where they're being stretched to the very limit. I wouldn't expect too much of an improvement, personally. But then I never really found it that much of a nuisance in the first place.