A cheap coilover kit would work the cheapest I've found it is 400 which is a steal cause they range from 800-3000 depending on brand and all that good stuff check out raceland if yours is a 3 sedan between 04-09 they will fit idk about the 10-12
i have the same problem on my mazda3 and i have 150k on it, milage means nothing .its more than likely the links make sure they are well tightened and if they are i would go to a mechanic to get it diagnosed and that way you know for sure what it is.
I think 18 with a +35 off set soul look sick right now I'm going to get some 17's with either a 20 or 25 offset I'm debating on it I had put some of my brothers old set that had a 25 off in the front and a 30 in the back but they were 18's
U have 13k on my mazda3 I thought they would be a problem with the cops but I've never been pulled over before my brother was running 15k on his rx8 nd never got pulled over so it shouldn't be a problem with the cops