Hi there, so I am looking at buying an MR2 very soon and I have a few questions regarding getting a RWC (first car in Australia for me).
What aftermarket parts would make it fail from getting a RWC? I am looking both in the ACT and outside the ACT, and obviously if I bring an interstate MR2 I will need to get a RWC and I want to make sure I don't end up buying a car that I can't register without having to buy a bunch of stock parts for it.
 
For example:
CT20b turbo = even if it works perfectly, would I fail the RWC because I need an engineer certificate for it?
18" rims = 3" bigger than stock, therefore cannot pass even if overall diameter is less than 7% different?
Aftermarket struts and/or coilovers?
Lowering the car?
I was also looking at a car with an engine swap: gen 4 motors from a toyota caldina?
 
I don't know who to ask so I hope I can get some help here.
Thanks!

You won't have any issues changing a CT26 to a ct20b, they're a toyota turbo, and an equivalent replacement.
 
in reality the CT20b is just a later version of the CT26, its just been called the CT20b by people over it's life so just retained that name.
 
18" rims will depend on your state. A lot of states have ditched the + x" rule in favour of a rolling diameter rule, so check with the relevant states that you will be travelling in.

hi alex the rules in act have changed and i think any imports have to go through dickson motor registry. wheels are based on the rolling diameter so with the right tire size you can have 18s. Coilovers are no good (apparently if you weld the adjusters they will let you have them) in regards to turbos the main thing they worry about is emissions so factory ecu, cat converter airbox blow off valve are the main things they will look for. The trade off in the act is that once you have rego you dont have yearly inspections.and unless you get a defect for.something obvious you can do what you want once you get rego. so look for a car with limited.mods or one that can be returned to stock easliy

Thanks guys, that's super useful info!
Lowering springs would be ok provided they don't lower the car too much/ reduce the shocks movement too much?Good to know about tyre diameter; also it looks like we are still not allowed to have more than 25mm wider than stock (If I recall correctly).

the 25mm measurement is the cars track,measured from centre of tyre to centre of opposite tyre it relates more to your offset rather than tyre width it becomes an issue with modified diffs im not sure if you could fit wheels under the mr2 that could be that far out

I am sure that you have checked this page already, but just in case 
http://www.rego.act.gov.a...strations/regomain.htm

Springs should be fine as long as you maintain the minimum ride height of 100mm (or whatever it is these days), and that your nothing fouls your suspension/body at the extremities (e.g. bottoming out).

Thanks everyone :)
Yeah it looks like it should be all fine except for that: 'High flow 100cfm catalytic converter" that is installed on the car I am interested in, which it looks like is illegal in all states unless that changed recently. I believe it needs to be 200cfm or more to be legal?

Hi Alex,
The Hi flow cat passed in Adelaide, here they only check to see that it is heating to the required temp, to ensure it is working / doing its job and hasn't been gutted.