sparks works only with some car

[Marco_il_bello]

hi,
i'm using Vr and i noted that if i use Benetton B191 the sparks are working but i run with f12022 cars or Lotus Exos Stage1 i've no sparks
any idea ?
and the aesthetics of the tires not change anymore in any cars.. d'u know why ?
i remember when the tires get consumed they used to change also the aesthetics
any idea or any tips/suggestions?
thx