"The first time, shame on you. The second time, shame on me."

sounds to me like your brother is doing something to draw attention to himself from thieves. He is doing something that is making him susceptible to his car being stolen. A thief is looking for easy money, they aren't going to take a car they know they might have trouble with.

Your brother might want to re-evaluate where he parks, where/how he drives, and how he modifies his cars. Also he might want to change the way he advertises his cars. The more people that know about your car, the more who know what you have, the more thieves that know. It's as simple at that.

as for the AV6MT goes-- you can get them for cheap because of the mass amounts of people flocking to buy the Si's..

if you haggle and get quotes online from dealers you should be able to get what you want for no more than 25k out the door in the north east.