1999 1.8 middle bench - destham
My 1999 Zafira has a lap belt in the middle seat of the middle bench. I am actively looking for a middle bench with the middle seat having a 3 point seat belt. Should I acquire it, would it be reasonable for a local service garage to install it for me?
1999 1.8 middle bench - yorkiebar
So you want a garage to install a seat belt where the manufacturer has not provided a safe and tested fitting?

Not sure you quite understand what you are asking. :)

If you were to find such a fitting, and a garage willing to do it; then I would suggest not to touch them under any circumstances!

I cannot say strongly enough how bad this idea is! Please do not consider it further!
1999 1.8 middle bench - Victorbox
I think destham wants to source a bench seat from a later Zafira A which does have a three point fixing middle seat belt and then get a garage to fit it. I must admit I though all Zafiras had three point seatbelts but I must be wrong.
1999 1.8 middle bench - SpamCan61 {P}
Nope, pre facelift Zafira A (even elegance model) like SWMBO's have a lap belt only in the middle.
1999 1.8 middle bench - Victorbox
A Zafira B is a wider vehicle than a Zafira A so I guess the bench seat won't fit even if the Flex 7 sliding mechanism is similar. Probably wouldn't be cheap even if you could locate one in a scrapper.
1999 1.8 middle bench - yorkiebar
Regardless of whether it would fit, or if its pricey !

To do this would mean securing a seat belt to somewhere that has not been designed or tested for it.

Please unserstand this is so safety critical it should not be entertained !
1999 1.8 middle bench - SpamCan61 {P}
From memory the middle belt in the facelift Zafira A is fastened into the roof ( like in a mk2 scenic ) , not 100% sure, so that would be a dashed tricky retrofit, unless the load point for the belt is lurking under the headlining in earlier zafira As.
1999 1.8 middle bench - johnsnc
Wrong I'm afraid. The three point harness was added in 2003 and goes nowhere near the roof. It is integrated into the seat assm. I would assume what the OP is planning to do is indeed viable. I'm sure I've seen mention on Vauxhall Owners Network site of this being done.
1999 1.8 middle bench - Screwloose

Regardless of the Vauxhall Owner's Network's view; is this modification Vauxhall [type?] approved?

Either way; the OP's insurers must be advised of a safety-critical modification and would probably want an engineer's report before reinstating his cover.
1999 1.8 middle bench - SpamCan61 {P}
I did look into doing the same modification on my old Omega estate, but I gave up given the combined hassle of insurance plus dealers telling me it couldn't be done, although it looked like it could. I suppose, from a stuctural point of view, it depends on whether Vx beefed up the middle bench mountings on the Zafira A to account for the fact it's a load bearing structure once the middle seat belt mounting is attached to it.
1999 1.8 middle bench - roosterbooster
obtian a middle row seat from a salvage yard 2004 onwards and it should fit fine like for like