Ebay kits won't ever send you a new shock when your shocks blow & they will. I had a JT Auto Styles kit for about a month and 3 days before a car show the driver side shock blew on me.

How you can tell the shock blew is like this;; It was raining out & I went to open the door, I didn't even lift the door up. The kit is the one that you push out then up, its good for every day users.
Any how when I done so I heard a PPPPSSSSTTT! Then tons of smoke, I thought I fucked something up with in the car, needless to say the door was not moving it was lower then what it should so it was hard to move, the door was for sure not use able.

3 days before a show, I next day'ed the shock to JT they then next dayed it back to me I had it 4 hours before the show. You lift the door up having someone prop it for ya and you squeeze your hands back in the fender & you clap it back in.

My kit is a bolt on, I forgot who on the thread stated you may want to add more then the standard bolts. Reason behind that is because as for my self the fender will become fucked up because there is only a few bolts holding up a very heavy door. I have a Celica & the door is surely not light by any means.
My fender became such a mess, took the body shop a day to fix each fender. When the doors are up the wind blows your doors an makes 'em sway due to the lack of support on the kit. You can't do anything about it other then buying a autolock or auto loc lambo kit that is a weld on kit. Only one I can honestly tell you that is worth your money.

But back to subject why Ebay kits suck, the metal / way its made can make it or break it. Your best bet is to keep your stock hindges near by after a few weeks if you make it that far you'll end up putting stock hinges because you may fight the lift of having to struggle lifting the kit up every day but when you have someone who isn't as or near strong enough to fight with the doors you'll find your self having to always open the door.

WD40 will be your friend for a few weeks. But you'll find your self kicking your self in the ass for buying a 299.99 Ebay kit, here are decent kits, price is up, but you pay for what you get bud.

eBay Motors: 2 Nitrogen Gas Shocks Fit Vertical Lambo Door Kit W/END (item 250269089441 end time Jul-15-08 17:00:00 PDT) <--- That you'll need to get, I am looking into the bigger size shock to toy around with how easy it is to lift the door. I'll let you know when I've tried it, gotta' call JT Auto Styles up in the next month.

http://www.customautotrim.com/bodyki...oors_index.htm
I've seen this kit before in person, smooth up & down, just don't go up as high but it goes out wider for the every day kind of guy. I rate this kit a 8.

http://www.customautotrim.com/bodyki...ex_autoloc.htm
Never seen or tried this kit to this date, I've only ever heard good things, guys who have Vertical doors say if they had the cash they would buy this kit. Leaving me to think this has to be a better kit. They also make Motorized Upgrade Lambo Conversion Kit for the door kit too. That will avoid the hassle to lift the door every now & then. I would think the shock would blow sooner but if you have a LIFETIME WARRANTY it won't matter.