Yesterday I fitted my brand new alloys

they look fantabulous I shall post some pics wen i have time
Only problem is...
I now sound like a train

Ive checked the wheels there bolted on tighter than scotsman (no offence 2 the scots on here

) There running round fine and dont rub or anything. The wheels are 18" 225/40R8 there fitted on 20mm spacers
But wen goin slow there is a knocking sound its disappears wen accelerating but as soon as i let of the gas abit there it is again! Im assuming this could be something to do with the suspension knocking

any ideas ppl? also my tyres outside sound like a dog panting as they go round

is this just tyre pressure not right??
I jus had a look at the tyres an on each tyre there is >>>ROTATION>>> and being the plum I am i have of course fitted ALL the wheels rotating the other way

do you thing this could be anything to do with it? I wouldnt expect it to but its driving me mad!