This bugs me too. I wish you add this little function (writen in lua)
It opens the new window only for the first new vehicle in the depo.
it is connected to the Buy button insted of the current one.
function ComfortOpenWindow ()
for i,car in oCurrentDepot do
if car.age = 0 then return end
OpenWindow () — this function opens window right now
Little step for programmer but huge leap for playerkind.