Before I get to first impressions i'll just say doing this with a friend would be a million times easier and probably cut the time in half. It took me pretty much 6 hours was a break for food and lots of water since its 115 here in phoenix.
That being said I used the kies motorsports video where Bryan puts the sport H&R springs on his recently deceased 328i, RIP. It was very helpful and the job is fairly straight forward.
First impressions, wow it is low. I maybe have 5" ground clearance on the side skirts. My drive has a rather large bump to get over and backing out straight I did scrape. Going in angled worked like a charm though. The ride is not harsh but definitely felt sportier. I'll give the springs time to settle but overall I'm happy with the look and now with all the performance mods and these springs I think i'll be getting some 18" wheels and fatter tires next. The 225s break away before half throttle
