"smooth ride" and coilovers really dont go in the same sentence, unless youre talking about teins. the basic's are good, ive never heard of any problems with them. warranties....i have no clue on. most of these people dont have the car or suspension long enough to claim a warranty on it from a defective part, haha, so theres really not much to say about that. you probably wont need to use it tho. tein, tho an old design, does make a good product. as for the wheels....nahh.