Asplitrearaxle.

　　Therearwheelsareindividuallysuspended,toadjusttotheshapeoftheroad.

　　(MostEuropeanracershavethis,butfewpassengercars.)

　　Taketheopposite:therigidrearaxle.Whatifyourcarhitsaruthole?

　　Clunk.

　　Seasoneddriverswaitforthisthump.

　　InaVolkswagen,itnevercomes.

　　“IvebeentoolingaroundinmyVolksfor3years,”saysonecommuter,“andI‘mstillsurprisedwhenthejoltdoesn’tcome.”

　　Volkswagenalsohavetorsionbarsuspensiononallfourwheels.(Notmanypassengercarshavethis,either.)

　　Ordinaryspringscan“hitbottom.”VWtorsionspringstwist.Themoretheytwist,themorespringtheydevelop.Thiscradlesthecar.Yougetasure-footedrideoverroughterrain.

　　Crookedwheels?

　　ThatswhatkeepstheVolkswagenonthelevel.